12. Karyotyping Flashcards
Trisomy 21
Trisomy 18
Trisomy 13
Turner’s Syndrome
Fanconi’s Anaemia
reciprocal translocation
segments from two different chromosomes have been exchanged
Robertsonian translocation
an entire chromosome has attached to another at the centromere; (only chromosomes 13, 14, 15, 21 and 22).
Rings
a portion of a chromosome has broken off and formed a circle or ring
Isochromosome
a mirror image copy of a chromosome segment including the centromere
Interstitial deletion
DNA lost from middle of chromosome
Terminal deletion
DNA lost from end of chromosome
Cri du chat syndrome
Severe mental development problems
small head
unusual facial features
Fanconi’s Anaemia
Increased pigmentation
Bone marrow failure
Increased risk of neoplasia
Numerical sex chromosome abnormalities
Minimal effect on survival of foetus
Balanced translocations
Usually no phenotypic effect