TLS Online TPP Program

#Question id: 12490


Tay-Sachs disease shows autosomal recessive inheritance. Parents of a newly diagnosed affected child are referred for genetic counselling. It would be correct to tell them that:

#Part-B Specialized Branches in Biotechnology
  1. the probability that their next child will be affected is 1 in 2.
  2. the probability that the older unaffected sister of the affected child is a carrier is 1 in 2.
  3. the fact that their last child was affected means that their next three children will not be affected.
  4. the probability that each parent is a carrier is 1.