Question

describe the development of an individual with that condition from the point of an undifferentiated embryo through birth and following puberty of: Swyer Syndrome (SRY mutations) in XY individual (compare with typical XY)

Answer 1

The Swyer Syndrome (SRY mutations) in XY individuals tend to affect the sexual development and it causes hypogonadism with a karyotype of 46, XY. They have external female genitalia with the development of fallopian tube and uterus that functions normally but the gonads which are ovaries or testes are not functional. They are female on the external, but the gonads are not functional, and they consist of streak gonads which are fibrous tissues. They will not be able to undergo puberty if the streak gonad is not treated.

The reason why there is a defect is because they do not function as normal XY fetus which develops testes. During the second month of gestation, many genes together function and hence helps in proper development. One of the genes which helps in normal development of the testes is the SRY gene: this gene helps in determining the sex of Y-chromosome and when there is a mutation in the SRY gene, it causes the syndrome due to lack of proper gonads. When the SRY gene is defective, gonads fail to differentiate into testes and hence it is not able to produce testosterone failing developing of many male organs. When there is antimullerian hormone not produces, the Mulluerian ducts tend to develop more of female organs like uterus, cervix, fallopian tube etc.

In the adults, if the syndrome is not treated there is no puberty and due to inactive gonad it will not be able to produce estrogen. Hence, there will be no menstruation along with no development of breast and uterus. The gonads will also not be able to produce progesterone and eggs and hence they will not be able to reproduce.