Chromosomal abnormalities case studies Flashcards
1
Q
Jacob’s syndrome
Chromosomal abnormality
A
- Male offspring receives an extra copy of the Y chromosome from father, resulting in XYY genotype
- Not inherited, but occurs due to the random attribution of an extra Y chromosome to a sperm during spermatogenesis (meiosis II)
- Low frequency of 1 in 1000 births
- Mild effects on the individual: increased risk of comorbid conditions like asthma, autism, and learning difficulties, as well as taller than average height and large head size. May cause infertility
- Condition is not hereditary
2
Q
Triple X syndrome
Chromosomal abnormality
A
- Genotype: XXX
- Caused by a random error in cell division, usually the non-disjunction of the X chromosome in either the mother or father
- Mild effects, including taller than average height, kidney problems, and flat feet. May cause intellectual disabilities or behavioural problems
- For the most part, the effects of Triple X syndrome are not profound because X-inactivation mechanism deactivates the other 2 X chromosoes in females with this condition
- Condition is not hereditary