Question

You are interested in sex determination.

A. If a patient had a mutation in a gene that was active in late testes differentiation, would the patient show as male or female? What phenotypes would the patient show?

B. Two male patients show up in a fertility clinic. Their genomes were examined. One was found to be XX, sry+, while the second patient was found to be XX, sry-. In ONE sentence, explain how the two men could be XX. Would these men be fertile (i.e., able to have children)?

Answer 1

Ans a) It completely depends on the type the mutation that takes place. Due to the mutation in the SRY it leads to failure of testicular differentiation in embryogenesis and this leads to formation of female phenotype. It leads to formation of the gonads as ovotestes.

Ans b) The two man can be XX which is a rare congenital condition where female genotype has phenotypically male characteristics. It is majorly due to unequal crossing over. The X in SRY gene combines with normal X from mother during the process of fertilization, it forms XX male. No, they are not fertile enough to produce babies