Question

Please provide a detailed explanation.

63. The accompanying pedigree concerns a rare inherited dental abnormality, amelogenesis imperfecta. S SIS a. What mode of inheritance best accounts for the transmission of this trait? b. Write the genotypes of all family members according to your hypothesis.

Answer 1

A) X- linked recessive is the best mode of ingeritance for this amelogenesis imperfecta disease. As you seen that parents are unafffected but some of the offsprings are affected. This suggests that the disease is recessive in nature. The gene is inherited by the sex chromosome because the trait is specific to one sex.

B)

Let XA encodes normal phenotype where as Xa encodes abnormal trait.

Please look in the image for genotype:

ΤΩΙΙΙ ΙΟΙΙΟΟ ΙΟΙΙΟΟ IICIUNUIICO LLLC XAY XIXa “XÂY |Xa XAXA | Or XAYa XAY XAXa W. XAXA- or XAXaXAY XÂY fibrin XaY XAXa XaY or XAXA or XAXA can be