Characteristics of a Down syndrome : Characteristics of a Down syndrome 1. Broad skull
2. Short stature
3. Stubby hand and feet with characteristic skin creases.
Slide 3 : 4. Low intelligence (or mental retardation) but are capable of learning many skills. Inspite of their handicaps, they are often happy and affectroriate.
5. Most foetuses do not survive until birth.
6. They have epicanthal folds (which caused this syndrome to be called mongolism originally)
Down hand/ foot : Down hand/ foot
Slide 6 : Do you know what frequency of people suffer?
1/700 births in women aged 25 years or under.
The frequency increases with age to about 1/100 for women of age 40 and 1/10 for women of age 45. Down syndrome
What is the Cause ? : What is the Cause ? Most cases of trisomy 21 are the result of non-disjunction during meioses.
Non disjunction occurs in both males and females
Although more common associated with females.
ALZEIMER'S DISEASE : ALZEIMER'S DISEASE A disabling neurological disorder
Afflicts about 11% of the population over age 65.
Causes are exactly unknown,
Effects are irreversible and devastating,
Has no cure.
Slide 9 : Fourth leading cause of death among the elderly in Western countries, following heart disease, cancer, and stroke.
The patients of Down syndrome have been frequently observed to exhibit Alzeimer's disease.
Symptoms of ALZEIMER'S DISEASE : Symptoms of ALZEIMER'S DISEASE 1. Initially persons lose memory, become confused and forgetful.
2. They often repeat questions and get lost while traveling to previously familiar places.
3. Gradually disorientation grows, memories of plant events disappear and show evident changes in then wood.
Slide 11 : ALZEIMER'S DISEASE
Slide 12 : 4. They lose the ability to read write, talk, eat or walk.
5. Finally the disease end in dementia, he loss of reason and ability to care for oneself.
Slide 13 : Cause
Probably related to chromosome 21
As people with Down syndrome also exhibit data amyloidal - containing plaque (abnormal proteins in brain) as seen in Alzheimer's disease. Symptoms of ALZEIMER'S DISEASE
EDWARD'S SYNDROME : EDWARD'S SYNDROME Described by J.H. Edwards and his coworkers in 1960.
Most infants with this genetic 'disorder die at an early age, some 90% within their first six months. few have, however been reported to be a live in their ten year.
Trisomy 18 : Trisomy 18
Symptoms of EDWARD'S SYNDROME : Symptoms of EDWARD'S SYNDROME Mental deficiency
Multiple congenital malformation
Effecting virtually every organ system
Malformed ears (the helix of the ear is scarcely developed).
Receding chin
Laterally compressed lead.
Hands are short
Show little development of second phalanx.
Slide 17 : Frequency
This incidence is about 1/8000 case.
Greater among infants of older women.
Cause
Trisomy due to non-disjunction in meiosis.
Trisomy 18 : Trisomy 18 Chromosome compliment
The disorder is due to trisomy of 18th chromosome
Thus people have 46 + 18 the chromosome.
PATAU'S SYNDROME : PATAU'S SYNDROME Discovered and described by
K. Patau in 1960.
Also known as trisomy-13 syndrome.
PATAU'S SYNDROME : PATAU'S SYNDROME Symptoms
In children
Non-existent in adults
Severe symptoms result in early death .
Small brain
Mental retardness
Deafness
Numerous external and internal abnormalities
Cleft palate
Patau Syndrome : Patau Syndrome Cleft palate corrected
Slide 22 : Frequency
Most death occur within first three months after birth
Few live for about 5 years.
Occurs in about 1/20,000 new born.
Chromosome compliment
46 + 13th chromes (= 47)
Trisomy of 13th chromosomes.
Cri-du chat syndrome : Cri-du chat syndrome Characteristic moon like face
First reported by Leujene.
Slide 24 : Symptoms
Severe phenotypic anomalies.
Infants with this syndrome have a characteristic high pitched cat like cry (hence called cat cry syndrome).
3. Children are form with micro- cephaly (small heads).
4. They have characteristic moon like face and severe mental retardation.
Slide 26 : Cause
Due to deficiency and deletions in chromosome number 5
If the deficiency is large enough and homozygous it will be lethal
SEX CHROMOSOMAL DISORDERS : SEX CHROMOSOMAL DISORDERS Involves numerical changes in the sex chromosomes (X and Y)
Sex chromosomal disorders : Sex chromosomal disorders
Turner Syndrome (44 + XO) : Turner Syndrome (44 + XO) Associated with female chromosomes
Phenotype described in 1938 by H.H. Turner and associates
Slide 31 : Characteristics
1. The adults females have virtually no ovaries (or reduced) and are sterile.
2. The secondary sexual charaters are limited and they
3. Individuals are short statured with webbed neck, low set ears and shield like chest.
4. Their mental capacity is reduced
Turner : Turner
Turner syndrome : Turner syndrome