Edson Arantes di Nascimento remains the most famous footballer on earth – more than 30 years after his retirement – and it is his World Cup achievements which have chiefly garnered that accolade. Diego Maradona may dispute that statement, and a feud with his fellow South American has long raged over who can regard himself as the best, yet Pelé would argue that he got there first.

The crowning moment: Pelé celebrates winning his second World Cup final

At a time when the world was being introduced to television coverage of a tournament that was still to get into its stride, Pelé and Brazil helped shape the World Cup into the greatest show on earth. Indeed, any great team must measure against those from his twin victories of 1958 and 1970.

An achievement of scoring over 1,000 career goals is amazing, but the Pelé of Sweden and Mexico remain the images the world will remember him for long after he has ascended to football heaven. The first saw him arrive as an unknown teenager and depart as the most glittering star in a galaxy of samba talent. The latter saw him cement his place in history as the conductor of the most devastating attacking force that has yet played at a World Cup.

After less than two years as a professional, and at just 17, he became the youngest player to play in the finals. Santos, the club side with whom he stayed right up until his first retirement in 1972, became envied around the world as their tyro, standing at just 5′ 8″, revealed his array of talents. Pace was matched with power, a fierce shot married to an instinct for opportunity, while a delicacy of touch coupled with a supreme athleticism and the physique of a welterweight boxer.

On arriving in Scandinavia, he was made to wait until Brazil’s third group game with the Soviet Union before being given his head, with Garrincha also being selected. He did not score, but strike partner Vavá grabbed the brace that took the team through to the last eight.

It was against Wales, making their so-far only finals appearance, that Pelé scored the goal he would call the most important of his career before France were swept away by a thrilling hat-trick in the semis. The final saw Brazil haul back an early lead for hosts Sweden with a four-goal salvo shared by Pelé and Vavá. One of the teenager’s pair saw him control the ball, hook it over his shoulder in one movement and smash in an unerring volley. Six goals in three games had already sealed his place in the tournament’s history.

Pelé (right) scored his first World Cup goal in the 1958 quarter-final with Wales

Chile in 1962 was expected to be further confirmation of supremacy, yet Pelé injured his hamstring in the second match and missed out on his country’s second successive World Cup win as Amarildo, known in less enlightened times as the “White Pelé,” took his chance and scored in the final.

Four years later, he was again struck by injury, after becoming the victim of some disgraceful tackling from Bulgaria and Hungary as Brazil shockingly crashed out in the first round. An ageing team could not cope with the strong-arm tactics they faced, but the image of a stricken Pelé wrapped in a blanket by the side of the Goodison Park pitch as the decisive match turned in Portugal’s favour was a harrowing sight to his legion of admirers.

Mexico 1970 is the tournament that fully cemented Pelé’s position at the head of World Cup legends. His experiences in England had caused him to proclaim he would never again play in a World Cup. He refused a 1969 call-up for the Selecao only to be persuaded to reconsider and declare that Mexico would be his last tournament.

There, while Carlos Alberto was granted the armband, Pelé was the Brazil team’s true leader. When, in the semi-final, Brazil had conceded early to Uruguay, so long their bête noire in the World Cup, it was Pelé who could be seen imploring his team on to better efforts and a place in the final.

By then he had provided some of the tournament’s finest moments. And they didn’t even result in goals. The salmon-like header to provide Gordon Banks with save of the century, an amazing shot from the halfway line against Czechoslovakia which just missed its target and a delicious combination of feint, dribble and shot just wide of the post against Uruguay are among the World Cup football’s enduring images.

Gordon Banks makes the save of the century from Pelé’s downward header

His opener in the final against Italy, an object lesson in the bullet header, made him only the second player to score in two World Cup finals. Old oppo Vavá had achieved the same in 1962. The pattern of play that forever sealed Brazil ’70 as team of the century owed its coupe de grace to the vision of the man who was easily first among near-equals like Gérson, Jairzinho, Rivelino and Tostão.

With the game in its dying embers, Clodoaldo weaved past tired Italian legs before the ball eventually found its way to the feet of Pelé.

He retained possession and the attention of Italy’s defenders before sliding the ball to his right where Carlos Alberto was cruising into a shooting position. The delicacy of Pelé’s pass gave the defender the perfect angle to defeat Albertosi from the edge of the box with a rocket of a shot.

Pelé was soon to be carried high from the Aztec Stadium’s pitch, able to take his leave of the World Cup for the final and most glorious occasion.

Fab spares Terry ‘destruction’

An England insider has informed Tellmeonline that Fabio Capello’s decision to axe John Terry as captain was taken to save him from being “destroyed” by the media scrutiny on his private life.

Many disease states arise from genetic alterations in cells after the earliest stages
development of the zygote; this group excludes those which affect the gonads (those are cases
of gonadal mosaicism).
Genetic alterations in the zygote after the first cell division may result in numerical
alterations with the formation of mosaics (discussed under chromosomes disorders). Other
alterations occur much later and may be inconsequential (as the genes are still complete), may
be lethal to the cells involved (the loss can be tolerated by the tissue), or may result in disease
conditions. A good example is in the development of neoplasm.
Genetic alterations underlie all forms of cancer. Though some cancers are hereditary,
most forms develop as a result of somatic cell genetic mutations resulting in the activation of
proto-oncogenes, inactivation of anti-oncogenes, or in the derangement of the regulation of
genes that control apoptosis. (for more on this please refer to the lectures and notes on
neoplasia.)
Mutations occurring in somatic cells are not transmissible.

This group of disorders can be classified into 4 categories
- disorders caused by mutations in mitochondrial genes
- diseases caused by triplet-repeat mutations
- disorders associated with genomic imprinting
- disorders associated with gonadal mosaicism
Mitochondrial Gene Disorders
Though most mitochondrial proteins are encoded by nuclear genomes, human
mitochondria contain about 2 – 10 copies of a circular double stranded DNA which code for
several proteins in the mitochondria. These mitochondrial chromosomes are self-replicating
and encode several enzymes involved in oxidative phosphorylation.
Mitochondrial DNA of the zygote is derived exclusively from the oocyte so that
Mitochondrial gene disorders have a maternal form of inheritance. Mutations in copies of
mtDNA are passed on randomly to subsequent generation of cells so that during growth of the
fetus later, it is possible to contain virtually only mutant genomes (mutant homoplasmy),
whereas others have only normal ones (wild-type homoplasmy). Most others will have a
mixed population of mutant and normal mtDNA (heteroplasmy). For this reason, clinical
expression of a disease produced by a given mutation of mtDNA depends on the total content
of mitochondrial genomes and the proportion that is mutant. The fraction of mutant mtDNA
must exceed a critical value for a mitochondrial disease to become symptomatic. This
threshold varies in different organs and is related to the energy requirements of the cells.
Clinically important mitochondrial DNA mutations are rare. Diseases caused by
mutations in the mitochondrial genome principally affect the nervous system, heart and
skeletal muscle. The functional deficits in all these disorders can be traced to oxidative
phosphorylation (so called OXPHOS diseases. OXPHOS diseases can arise from nuclear
mutations and from mtDNA mutations).
The first to be described example of mitochondrial gene disorder is Leber’s
hereditary optic neuropathy. This is a neurodegenerative disorders that manifest itself as
progressive bilateral loss of central vision. It leads in due course to blindness. Other examples
are some of the so-called encephalomyopathies including Kearns-Sayre syndrome.
Triplet-Repeat Mutation diseases
These diseases are due to mutations which are characterized by a long repeating
sequence of three nucleotides. Although the specific nucleotide sequence that undergoes
amplification differs from one disease to another, in most cases the affected sequences share
the nucleotides guanine (G) and cytosine (C).
The prototype of this group is the fragile X syndrome

FRAGILE X SYNDROME
This is the second most common genetic cause of mental retardation.
The genetic defect lies at the distal end of the long arm of the X chromosome. Careful
examination of the karyotype of affected individuals’ lymphocytes, cultured in a folatedepleted
and thymidine-depleted medium, reveals a constriction followed by a thin strand of
genetic material that extends beyond the long arm at the highly conserved band Xq27.3. This
constriction and thin strand produce the appearance of a fragile portion of the X chromosome,
leading to the term fragile X.
The function of the band Xq27.3, which is also termed the fragile X mental
retardation-1 (FMR1) gene, is to synthesize fragile X mental retardation protein (FMRP), a
regulatory protein that binds messenger RNA (mRNA) in neurons and dendrites. In patients
with a full mutation in the FMR1 gene, FMRP is not manufactured because of
hypermethylation of FMR1, and brain development is impaired primarily because of
abnormal synapse connections. FMRP is present in other tissues; however, its role is less
understood.
Once identified and sequenced, the gene was discovered to contain a repeating base
pair triplet (CGG) expansion, which is responsible for fragile X syndrome. Unaffected
individuals have 5-54 CGG repeats in the first exon at the 5′ end of band Xq27.3. A span of
55-200 repeats is known as a premutation, whereas more than 200 repeats is a full mutation.
The defect is dynamic; the number of repeats is unstable from generation to
generation, making the pattern of inheritance difficult to predict.
Males with a full mutation have fragile X syndrome. Mothers of all males with fragile
X syndrome have premutation or fragile X syndrome. Males with fragile X syndrome pass a
premutation to their daughters because sperm cells are mosaics. Sons are unaffected because
they receive the Y chromosome from their fathers.
Males with a premutation are usually unaffected to mildly affected and transmit the
premutation to their daughters. The mutation is stable; thus, the CGG triplets are not
increased. Sons of affected males are unaffected because they receive the Y chromosome
from their fathers.
*Females with a premutation are usually unaffected to mildly affected. Unlike their
male counterparts, the CGG triplets are unstable and increase in size during oogenesis. If the
number of repeats exceeds 200 and the oocyte is fertilized, a male child will have fragile X
syndrome, and a female child will have a 50% chance of having fragile X syndrome. The
number of repeats is directly proportional to the risk of the disorder in an offspring.
Other examples of triple-repeat mutation diseases include Friedrich ataxia, Myotonic
dystrophy, Huntington disease, and various types of spinocerebellar ataxia
Gonadal mosaicism
This results from mutations that occur postzygotically during embryonic development.
If the mutations affect only cells destined for the gonads, the gametes carry the mutation but
the somatic cells of the individual are completely normal. This accounts for many cases of
appearance of, for example, an autosomal dominant condition in an offspring of normal
parents, eg in osteogenesis imparfecta, and these parents may have more than one affected
offspring.
Genomic imprinting
Functional differences have been shown to exist in allelic pairs of certain genes
between the one of paternal origin and the one of maternal origin. These differences result
from an epigenetic process, called imprinting. In most cases, imprinting selectively inactivates
either the paternal or maternal allele.
Prader-Willi syndrome and Angelman syndrome are examples; these two disease
result from an interstitial deletion of band 15q12. When this deletion occurs on the paternal
allele, Prader-Willi syndrome results, while deletion of the same on the maternal allele
produces Angelman syndrome.
Features of Prader-Willi syndrome includes mental retardation, short stature,
hypotonia, obesity, small hands and feet and hypogonadism. Patients with Angelman have
mental retardation, ataxia, seizures, and inappropriate laughter.

These result from combined actions of environmental influences and 2 or more
mutant genes having additive effect. A number of phenotypic characteristics are governed by
this pattern of inheritance eg height, skin colour, IQ, hair colour etc.
The concept of multifactorial inheritance is based on the notion that multiple genes
interact with various environmental factors to produce disease in an individual. Such
inheritance leads to familial aggregation that does not obey simple Mendelian rules. The rist
of expressing a multifactorial disorder is conditioned by the number of mutant genes
inherited; the probability of symptoms in first-degree relatives of a person affected with a
multifactorial disease is usually about 5 – 10%. The probability is considerable lower in
second-degree relatives.
The identical twin concordance rate, which is an indication of the relative role of the
genes versus environmental factors in the genesis of the disease, is usually significantly less
than 100% in multifactorial disorders. For most conditions, it is usually in the range of 20-
40%.
Examples include DM, gout, hypertension, atherosclerosis, coronary heart disease,
cleft lip/palate, congenital heart disease, psoriasis, breast carcinoma etc

Mendelian disorders are expressed single gene mutations that have a large effect.
A mutation is a permanent change in DNA. Mutations may occur in chromosomes
leading to alterations in structure, (as discussed earlier) or in the genes.
Gene mutations are submicroscopic and occur in 2 forms.
i. Point mutations
ii. Frame shift mutations
Point mutation is a situation in which a single nucleotide is substituted by another.
When this occurs in a coding sequence of the DNA, it may result in the replacement of one
amino acid by another in the gene protein product (a situation refered to as missense
mutation), or the new codon may code for the same amino acid (called synchronous
mutations, which will be clinically insignificant), or it may change an amino acid codon to a
chain termination, or stop, codon (a nonsense mutation).
A missense mutation is what occurs in what occurs in sickle cell anaemia while Bthalasssaemia
is an example of nonsense mutation.
In a situation in which the point mutation occurs in a non-coding sequence e.g. in the
promoter and enhancer sequences near a gene, it may affect adversely the expression of that
gene eg in B+ thalasemmia. Point mutations within introns lead to defective splicing and
hence an abnormal product.
Frame shift mutations result from insertions and deletions. This leads to alteration in
the reading frame of the DNA strand. If the number of bases involved is 3 or multiples
thereof, then a frame shift does not occur; rather an abnormal protein with extra amino acids
is synthesized.

CLASSIFICATION
Mendelian disorders can be grouped based on their transmission patterns into 3
classes:
i. Autosomal dominant
ii. Autosomal recessive
iii. Sex linked (or X-linked) disorders.
Although gene expression is usually described as dominant or recessive, in some cases
both alleles of a gene pair may be fully expressed in the individual, a condition called codominance.
eg MHC genes, blood group genes.
More definitions.
Pleitropism – is a situation in which a single mutant gene leads to many end effect.
An example is Sickle Cell disease in which there is hemolysis, organ infarcts, bone changes
etc., Marfan’s syndrome with changes in the CVS, skeleton, eyes etc.
Genetic heterogeneity – this is the opposite of pleiotropism. Here several genetic loci
produce the same traits. For example, Albinism and profound childhood deafness.

AUTOSOMAL DOMINANT DISORDERS.
These are manifested in the heterozygous state. Usually at least one parent of an index
case is affected. Both males and females are affected and both can transmit the condition. On
average, 50% of the offspring of an affected individual will be affected. When a disorder in a
particular is due to a new mutation, none of the parents will be affected.
Two factors may modify the clinical features. These are reduced penetrance and
variable expressivity. Reduced penetrance means that less than 100% of individuals who
inherit the mutant gene express the trait. Penetrance can be described as the proportion
exhibiting the trait amongst those who inherit the mutant gene. It is expressed in %.
For reasons of reduced penetrance, it follows that some phenotypically normal persons
may transmit an autosomal dominant disorder.
Variable expressivity describes a situation in which the features, though seen in all
individuals with the abnormal gene, are expressed differently among them.
In many AD conditions, age of onset of the disorders is delayed. An example is
ADPKD.
AD disorders usually affect structural and regulatory proteins (the latter include carrier
and receptor proteins) and generally tend to be less severe than the recessive disorders.
Examples of AD disorders include:
1. Neurofibromatosis.
2. Adult PKD
3. Familial adenomatuous polyposis coli.
4. Hereditary Spherocytosis
5. Von Willebrand’s diease
6. Marfan syndrome
7. Familial hypercholesterolemia

AUTOSOMAL RECESSIVE DISORDERS
This represents the single largest group of Mendelian disorders. Affected individuals
have mutations in both members of a gene pair, ie homozygous states. Usually, each parent is
a carrier and is unaffected. The occurrence risk when both parents are heterozygous is 25%
for each birth.
The expression of the defect tends to be more uniform than in AD disorders; complete
penetrance is common and onset is frequently early in life.
Many autosomal recessive traits affect enzyme proteins, which have a large safety
margin so that a reduction from the normal 100% activity to 50 in heterozygous persons does
not result in disease.
The chance of having a child with an autosomal recessive disorders is increased if the
parents are blood relatives (consanguinity). Although not a prerequisite, consanguinity is an
important clue that a disease is due to an AR trait.
As mentioned earlier, enzyme proteins are involved in many AR disorders among
which are all inborn errors of metabolism (glycogen storage diseases, mucolipidoses,
lysosomal storage diseases etc.), congenital adrenal hyperplasias, Other proteins that may be
affected in AR disorders include plasma proteins and hemoglobins. Examples of AR include
hemoglobinopathies, thalasemias and childhood PKD.

SEX-LINKED DISORDERS
All sex-linked disorders are X-linked (the Y chromosomes carries very little genetic
14
information almost all of which have to with determination of testes formation and with
spermatogenesis; consequently anomalies associated with these genes lead to infertility and
are therefore not transmissible). Almost all of these sex-linked disorders are recessive.
In the male, the X chromosome is paired with the non-identical partner Y; males
carrying X-linked mutant genes are therefore said to be hemizygous. X-linked recessive
disorders usually manifest in males whereas heterozygous females are carriers. Sons of the
carrier mother have a 50% chance of receiving the mutant gene and therefore manifesting the
disease while the same risk befalls the daughters but they end up as carriers. It is
understandable therefore that X-linked recessive disorders tend to show consistent male
severity in the family; female carriers are usually normal but may be occasionally mildly
affected because of the inactivation of one of the chromosomes in lyonization. If the mutant
gene is kept active in many of the cells in the target tissue then a moderate degree of disease
may result.
Examples include:
Hemophilia A, Hemophilia B, Red-Green colour blindness, Bruton’s
agammaglobulinaemia, G6PD deficiency, Duchenne’s muscular dystrophy, chronic
granulomatous disease etc.

Imbalance of sex chromosomes is much better tolerated than those of autosomes. This
is mainly due to lyonization of all but one X chromosomes and the small amount of genetic
material carried by the Y chromosome.
Lyonization refers to the inactivation of an X chromosome. This is outlined by the
Lyon’s hypothesis. The Lyon hypothesis states that:
i. only one of the X chromosomes in any cell is genetically active,
ii. the other X is rendered inactive.
iii. Inactivation of either paternal or maternal X occurs at random in all cells of the
blastocyst on or about the 16th day of life.
iv. This inactivation persists in all cells derived from each precursor cell.
The inactivated X can be seen in the interphase nucleus as the Barr body or X
chromatin.
Since the Lyon hypothesis was first outlined in 1961, a few modifications have been
made. It is believed now that expression of some genes from both X chromosomes is
necessary for normal growth and development. It has been shown that many X genes escape
inactivation (21% of genes on Xp and 3% of genes on Xq). Also both X chromosomes are
required for normal oogenesis.
The gene responsible for the process of lyonization is the Xist gene; the Xist allele is
turned off in the active X.
The Y-chromosomes is both necessary and sufficient for male development;
regardless of the number of X chromosomes, the presence of a single Y chromosomes
determines the male sex.
Sex chromosomes disorders generally induce subtle chronic problems that relate to
sexual development and fertility. Many are first recognized at the time of puberty. Significant
mental retardation is not usual with them but, in general, the higher the number of X
chromosomes in both male and female, the higher the likelihood of mental retardation.

TURNER SYNDROME

This is characterized by hypogonadism in phenotypic females. It results from complete or partial monosomy of the X chromosomes. About 57% of patients have a complete monosomy with a 45X karyotype. These 45X patients represent only about 1% of fetuses with the 45X karyotype; most conception with this complete monosomy do not survive to birth. The remaining cases of Turner syndrome, one third have partial monosomies which include deletions of varying portions of the X chromosomes with formation of ring chromosomes and isochromosomes, while two thirds are mosaics (eg 45X/47XXX, 45X/46XY). Patients with monosomy X are usually severely affected and with them diagnosis can often be made at birth or in early childhood, while in the other cases (ie mosaics and deletions), they may have an almost normal appearance and may present only with primary amenorhoea. Clinical features Presentation in infancy is with lymph stasis leading to edema of the hands and feet, and sometimes swelling of the nape of the neck (Here, a cystic hygroma, may be produced). Adolescents and adults present with webbing of the neck, short stature (rarely above 1.5m), and at puberty there is failure to develop normal secondary sexual characteristics. The genitalia remain infantile. Turner syndrome is the single most important cause of primary amenorrhoea. In the ovaries, accelerated loss of oocyte, beginning in utero, is complete by the age of 2 years. The ovaries are atrophic, fibrous, devoid of ova and follicles, and are called streak ovaries. Reduced estrogen output leads to high levels of pituitary gonadotrophins. Other features include broad chest with widely spaced nipples, pigmented nevi of skin and a marked carrying angle (cubitus valgus). Congenital heart disorders are also common particularly preductal coarcation of the aorta and aorta stenosis with endocardial fibroelastosis.

KLINEFELTER SYNDROME

KS is male hypogonadism occurring due to the presence of 2 or more X chromosomes in the presence of one or more Y chromosomes. eg XXY, XXXY. It is one of the most common causes of male hypogonadism and can rarely be  diagnosed before puberty. It is a principal cause of male infertility. The incidence of the syndrome is about 1 in 850 live male births. 82% of cases have the classic 47XXY; a little more than half of these result from paternal meiotic nondisjunction resulting in formation of an XY sperm while the remainder is of maternal abnormal XX ovum. Most other cases are mosaics with mostly 46XY/47XXY. Rare cases have 48XXXY or even 49XXXXY, these individuals with multiple X have further physical abnormalities including cryotorchidism, hypospadias, more severe testicular hypospadias, and skeletal changes such as prognathism and radioulnar synostosis. The consistent feature is hypogonadism with severely reduced or completely absence spermatogenesis. The testes show atrophic changes often associated with a small penis. There is lack of secondary male sexual characteristics (such as deep voice, beard, male distribution of pubic hair) and there is also a eunuchoid body habitus with abnormally long legs. Plasma gonatotropin levels are elevated whereas testosterone levels are variably reduced. Mean plasma estradiol levels are also elevated. IQ may be slightly reduced but there is usually no mental retardation. Others Supernumerary Y chromosomes may be found in the male, and multiple X in females (XXX); nearly all are phenotypically normal.

SEXUAL AMBIGUITY.

The sex of an individual is defined at various levels. i) Genetic sex is determined by the presence or absence of a Y chromosome. ii) Gonadal sex is based on the histologic characteristics of the gonads ie testicular or ovarian tissue. iii) Ductal sex depends on the presence of derivatives of the Mullerian or Wolffian ducts iv) Phenotypic or genital sex describes the external genitalia. Sexual ambiguity is present if there is a disagreement among these criteria for sex determination. True hermaphroditism means the presence of both ovarian and testicular tissue. Pseudohermaphroditism represents a disagreement between genital and gonadal sex. A male pseudohermaphrodite has testicular tissue but female genitalia. In female pseudohermaphroditism the genetic sex in all cases is XX and the development of ovaries and 11 internal gentalia is normal. Virilization of the external genitalia result from excessive exposure to androgenic steroids during the early part of gestation. The steroids are usually secreted by fetal adrenal gland affected by congenital adrenal hyperplasia. In male pseudohermaphroditism, there is a Y chromosome so that the gonads are testes but the genital ducts and external genitalia are incompletely differentiated along the male form. The external genitalia may be completely female. It has a multiplicity of causes but common to all is defective virilization of the male embryo, which usually results from genetically determined defects of androgen synthesis, actions or both. The most common form, called complete androgen insensitivity syndrome (or testicular feminization), results from mutation in the gene for the androgen receptor located on the long arm of X.

Down Syndrome.
Also known as mongolism, this is the most common of the chromosomes disorders.
About 95% have trisomy 21 (47XX or XY,+21). 4% have 46 chromosomes but with a
Robertsonian translocation, while about 1% are mosaics.
In the 95 with trisomy 21, meiotic non-disjunction is the most common cause. The
parents are usually normal in all respects. In most of these cases (about 95%), the extra
chromosome-21 is of maternal origin. Increasing maternal age has a very strong effect on the
risk. Mothers about 45 years have a 1 in 25 chance of having a Down syndrome baby. The
cases with robertsonian translocation tend to be familial with one of the parents being a
carrier of the translocation. Symptoms are milder in the mosaics. Maternal age is obviously of
no relevance in these last 2 groups.
Clinical features include:
a. Flat facial profile, oblique palpebral features and epicanthic folds. Brushfield spots
are found on the iris. A prominent tongue, which typically lacks a central fissure, protrudes
from an open mouth.
b. Profound mental retardation. IQ deteriorates over the first decade of life to a mean
of about 30.
c. About 40% have congenital heart defects, eg ASD, VSD, AV valve malformations.
This accounts for the majority of deaths in infancy and childhood.
d. There is a 10 to 20 fold increased in the risk of developing acute leukemia.
e. Virtually all patients with trisomy 21 above 40 years develop changes of
Alzheimer’s disease.
f. Patients are predisposed to serious infections and thyroid autoimmunity due to
abnormal immune responses.
g. GI disorders like duodenal stenosis, imperforate anus and Hirshsprung disease
occur in 2 –3 % of the children.
h. Men with trisomy 21 are invariably sterile due to arrested spermatogenesis.
Trisomy 18 (Edward syndrome)
Other trisomies eg 18 and 13 (Patau’s) are also related to maternal age. Malformations
are more severe than in down’s. Only rarely do the infant survive beyond the first year of life.
Most succumb within a few weeks.
Features of trisomy 18 include mental retardation, prominent occiput, micrognathia,
heart defects, renal malformations and rocker bottom feet. Many of these features are also
found in trisomy 13 where polydactyly and cleft lip and palate are the most characteristic
external manifestations.
Cri du Chat syndrome (del 5p).
This was so named because affected infants up to the age of one year have
characteristic cry of a cat. The often survive into adult life by which time the vocal
characteristics improve. Other features include severe mental retardation, microcephaly and
round face.
22q11 deletion syndrome.
DiGeorge’s syndrome and velocardiofacial syndrome were 2 clinically different
disorders with sometimes overlapping features. Both are characterized by the presence of a
deletion of a portion of the long arm of chromosomes 22 in the band 1 or region 1. They are
now grouped together under the above name.
DiGeorge’s was characterized by thymic hypoplasia with resultant T-cell deficiency,
parathyroid hypoplasia leading to hypocalcemia. VCF was characterized by facial
dysmorphism, cardiovascular anomalies and learning disabilities.
The acronym CATCH 22 was coined to describe this deletion syndrome (Cardiac
abnormalities, Abnormal face, T cell deficit, Cleft palate and Hypocalcaemia).

Knowledge is Power

Act of Reading

When it comes to Acquiring, it costs much to do so. A young gentle man was asked what he fears about the growth of his young lads, he replied, “I do fear if they don’t acquire knowledge. The beauty of any society is the ability to provide qaulity education, through which knowledge is acquired.

Another man was shown how nice it was to do a particular thing better, he marveled when he discovered that he would have done it better than he did.

The only better way of achieving great is to read and acquire the basic and necessary info. Every man has the right to knowlegde, when one is deprived of this all important thing in life, he/she is doomed for life. Imagine a man born into a family of 9 in African setting, 5 out of the 7 children were able to acquire basic knowlegde. In his side, left education in pusuit of wealth through “hustling” where he thought he would have made millions. When the other of his siblings persisted and left school, every other things became a story.

Give your child the best gift in life via Education, with this, he won’t grow to forget you in a hurry, and you will always be grateful to yourself in doing that.

Introduction to African Slavery

Slavery

The institution of slavery as it existed in Africa, and the effects of world slave-trade systems on African people and societies. As in most of the world, slavery, or involuntary human servitude, was practiced across Africa from prehistoric times to the modern era. When we talk about slavery, many envision the form in which it existed in the United States before the American Civil War (1861-1865): one racially identifiable group owning and exploiting another. However, in other parts of the world, slavery was in many different forms. In Africa, many societies recognized slaves merely as property, but others saw them as dependents who eventually might be integrated into the families of slave owners. Still other societies allowed slaves to attain positions of military or administrative power. Most often, both slave owners and slaves were black Africans, although they were frequently of different ethnic groups.

Traditionally, African slaves were bought to perform menial or domestic labor, to serve as wives or concubines, or to enhance the status of the slave owner. Traditional African practices of slavery were altered to some extent beginning in the 7th century by two non-African groups of slave traders: Arab Muslims and Europeans. From the 7th to the 20th century, Arab Muslims raided and traded for black African slaves in West, Central, and East Africa, sending thousands of slaves each year to North Africa and parts of Asia. From the 15th to the 19th century, Europeans bought millions of slaves in West, Central, and East Africa and sent them to Europe; the Caribbean; and North, Central, and South America. These two overlapping waves of transcontinental slave trading made the slave trade central to the economies of many African states and threatened many more Africans with enslavement.

Slavery within African soceity

The pratice of slavery existed in some earliest organized soceities in Africa, about 3,500 years ago, ancient Egyptians raided their neighbouring soceities for slavery, and the buying and selling of slaves were regular activities in cities along the Nile River. However, whereas the Egyptians left behind written records of their activities, most other early African states and societies did not. Therefore, our understanding of slavery in other parts of Africa is based on tales and oral histories from aged ones and on much more recent observations of African traditions regarding slavery and kinship.

Origin of Slavery in Africa

Slaves

As in many places around the world, early slavery likely resulted from warring groups taking captives. Such captives were of little use, and often some bother, when kept close to their homes because of the ease of escape. Therefore, they were often sold and transported to more distant places.

Warfare was not the only reason for the practice of slavery in Africa, however. In many African societies, slavery represented one of the few methods of producing wealth available to common people. Throughout the African continent there was little recognition of rights to private landholding until colonial officials began imposing European law in the 19th century. Land was typically held communally by villages or large clans and was allotted to families according to their need. The amount of land a family needed was determined by the number of laborers that family could marshal to work the land. To increase production, a family had to invest in more laborers and thus increase their share of land. The simplest and quickest way to do this was to invest in slaves. To help service this demand, many early African societies conducted slave raids on distant villages.

Effects of Slavery in Africa

• The spread of Islam from Arabia into Africa after the religion’s founding in the 7th century ad affected the practice of slavery and slave trading in West, Central, and East Africa.
• The demand for labor increased as plantation agriculture developed in the region, the East African slave trade increased dramatically.
• The culture of the East African coastal regions was strongly influenced by Arab and Persian traders, many of whom intermarried with Africans, thus producing the Swahili people and culture.
• Neighboring states competed with one another for trade, leading to wars, which in turn led to the capture of more slaves.
• As the demand for slaves grew, so did the practice of systematic slave raiding, which increased in scope and efficiency with the introduction of firearms to Africa in the 17th century.
• Historians estimate that between 1.5 and 2 million slaves died during the journey to the New World.
• In most of Africa, slavery became a more central, structural element of African life, as rulers and wealthy elites sought to accumulate more and more slaves, for sale as well as for their own use.

End of Slavery in Africa

As humanitarian sentiments grew in Western Europe with the 18th-century Age of Enlightenment and as European economic interests shifted slowly from agriculture to industry, a movement to abolish the slave trade and the practice of slavery came into being in the Western world. In 1807 the slave trade was outlawed in Britain and the United States.

The ending of the slave trade and slavery in Africa had wide-ranging effects on the African continent. Many societies that for centuries had participated in an economy based on slave labor and the trading of slaves had difficulty finding new ways to organize labor and gain wealth. Meanwhile, colonial governments in Africa that outwardly disapproved of slavery still needed inexpensive laborers for agriculture, industry, and other work projects. As a result, African leaders and former slave owners, as well as colonial officials, often developed methods of coercing Africans to work without pay or for minimal compensation. Moreover, the outlawing of slavery did not erase the pain and stigma of having been a slave. Many descendants of slaves were affected by this stigma for generations after slavery was abolished.