CYTOGENETIC DISORDERS involving autosomes Flashcards
It is the only human autosomal trisomy in which a significant number of individuals survive longer than a year past birth.
Trisomy 21
Who discovered Trisonomy 21?
Langdon Down
Most cases of Downs syndrome are caused by?
non-disjunction
This refers to the failure of homologous chromosomes to separate in meiosis
Non-disjunction
This nondisjunction is more likely to happen on oogenesis than in spermatogenesis.
Nondisjunction of chromosome 21
This copy of chromosome 21 is responsible for most of the malformation in a human being.
Third copy
Trisonomy 18 is AKA as?
Edwards syndrome
Trisonomy 13 is AKA?
Patau Syndrome
This is a rare conditions associated with major developmental abnormalities
Trisomy 18 (Edwards Syndrome)
Trisomy 13 (Patau Syndrome)
The following symptoms below refers to?
- Mental retardation,
- Multiple physical abnormalities such as heart defects,
- affected children are small in stature because
of delayed maturation of the skeletal system,
- Poor muscle tone resulting in a characteristic
facial appearance, Shortened life span
Trisomy 21
Who discovered Trisonomy 13?
Klaus Patau
In 1960, Klaus Patau and his associated observed an infant with severe developmental malformations with a karyotype of 47 chromosomes
Trisonomy 13
What is the average survival of Trisonomy 13?
Less that six months
These symptoms belongs to?
■ Affected infants are not mentally alert
■ Are thought to be deaf
■ Characteristically have a harelip, clef palate
■ Demonstrate polydactyly
■ Autopsy reveals congenital malformation of most organ
systems
■ Condition indicative of abnormal developmental events
occurring as early as 5-6 weeks of gestation.
Trisonomy 13
Who discovered Trisonomy 18?
John H. Edwards
What did John H. Edwards and his colleagues reported about Trisonomy 18?
infant trisomic for a chromosome in the E group
What is the survival of Trisonomy 18?
Less than 4 months
To which these characteristics belongs to?
- Congenital heart defects,
- growth retardation,
- dysmorphic features,
- facial clefts,
- spina bifida, -
- severe developmental delay
Trisonomy 18
To which does these CHARACTERISTICS belong?
■ Smaller than the average newborn
■ Skulls are elongated in an anterior-posterior
direction
■ Ears are set low and malformed
■ Webbed neck
■ Congenital dislocation of hips
■ Receding chin
Trisonomy 18
This disease is due to a missing piece (deletion) of a specific part of chromosome 5 known as the ‘p’ arm.
Cri-du-Chat
In general, the severity of the symptoms of Cri-du -Chat is determined by the size and location of the deletion on?
Chromosome 5
Infants with this condition often have a high pitched cat-like cry, small head size, and a characteristic facial appearance.
Cri-du-Chat
These symptoms belongs to?
○ Cat-like cry
○ Small head size (microcephaly)
○ Characteristic facial features
○ Hypotonia
○ Intellectual disability
○ Global developmental delay
○ Behavior issues
○ Growth delay
Cri-du-Chat
