Genetics

Question 1

what week does pregnancy screening for Down’s occur?

Answer 1

11 weeks

Question 2

cause of Down’s syndrome

Answer 2

trisomy 21

Question 3

what do you need to do a DNA or chromosome test on a baby?

Answer 3

tissue with the baby’s genetic makeup

Question 4

where can the baby’s DNA be attained from?

Answer 4

placenta
skin/urine cells
chorionic villus biopsy
amniocentesis 
mother's serum (placenta drops DNA into the mother's blood)

Question 5

cause of Patau syndrome

Answer 5

trisomy 13

Question 6

when is termination of pregnancy surgical?

Answer 6

before 13 weeks

Question 7

when is termination of pregnancy induced?

Answer 7

after 13 weeks

Question 8

when is there no time limit to termination of a pregnancy?

Answer 8

serious abnormality to the child

health risk to the mother

Question 9

define anencephaly

Answer 9

absence of a portion of the skull during embryonic development, max survival 1 day (same with Edward’s syndrome)

Question 10

what does non-invasive testing determine?

Answer 10

sex

trisomy (extra chromosomal material)

Question 11

what does invasive testing determine?

Answer 11

chromosome abnormalities

single gene changes

Question 12

when should aCGH or chromosome analysis be done?

Answer 12

high risk of trisomy
foetal abnormalities on scan
parents have balanced chromosomal arrangement

Question 13

causes of a floppy baby (hypotonia) that needs to be tested for rapidly

Answer 13

myotonic dystrophy
spinal muscular dystrophy
Prader-Willi syndrome