A man and woman both are carriers for sickle cell anaemia. What is the probability that both of the couple's twins will have sickle cell anaemia if both the twins are (i) Dizygotic (ii) Monozygotic?

Asked by Atulcaald | 15th May, 2018, 02:28: PM

Expert Answer:

Note that for each gene, there is a 1/4 chance of being homozygous dominant, ½ chance of being heterozygous (carrier), and 1/4 chance of being homozygous recessive.

S1 = twin 1 has sickle cell disease

S2 = twin 2 has sickle cell disease

The probability of having sickle cell anemia = ¼ x ¼ = 1/16  

Answered by Sheetal Kolte | 17th May, 2018, 12:10: PM