Friday, 28 November 2008

Genetics

Chromosomal findings in early miscarriage
40% normal 60% abnormal

Chromosomal abnormalities
1-number
2-structure


Downs syndrome-
1-trisomy 21
2-Robertsonian translocation
3-mosaicism

60% aborted
20%still birth

Robertsonian in Downs 96% denovo
21:21 trans location is 100% recurrence

Maternal age related to all trisomies

Autosomal recessive

Cystic fibrosis 1:2500 babies in U.K
Sex linked recessive
Duchenne Muscular dystropy free fetal DNA can be done to check the sex