Chromosome Abnormalities Flashcards
1
Q
What is aneuploidy?
A
Abnormal number of chromosomes (1 extra or 1 less)
2
Q
What is trisomy?
A
One extra complete or partial chromosome (47xy)
3
Q
What is triploidy?
A
A complete extra set of chromosomes (69xxy)
4
Q
What is Turners Syndrome?
A
45xo, missing and x or y from the fathers side
5
Q
What are 5 sonographic appearances of T21?
A
Thick nuchal fold >/=6mm Heart defect Echogenic focus in ventricle(s) Renal dilatation Duodenal atresia Shortened long bones
6
Q
Which type of trisomy is not detected with the triple screen?
A
T13
7
Q
What triple screen markers are associated with T18?
A
All low
8
Q
What is Alobar holoprosencephaly?
A
The most severe with little to no brain tissue and a horseshoe shaped ventricle and fused thalami
9
Q
How does triploidy occur?
A
60% fertilized with 2 sperm
40% fertilization of a diploid egg
