SNP Shot: Genomic Insights

17-beta hydroxysteroid dehydrogenase 3 deficiency is a genetic disorder primarily affecting the sexual development of individuals who are genetically male (XY chromosomes). These individuals possess testes but struggle to produce sufficient testosterone, a crucial hormone for male sexual differentiation. This testosterone deficiency significantly impacts the development of external sex organs before birth.

Consequently, most infants with this deficiency are born with external genitalia that appear female. Some may exhibit ambiguous genitalia, while others may have predominantly male-appearing genitalia, potentially including micropenis or hypospadias.

During puberty, individuals with this condition experience some development of male secondary sex characteristics, like increased muscle mass, a deeper voice, and the growth of facial and body hair typically seen in males. However, they may also develop gynecomastia. Despite having testes, these individuals are typically infertile.

Children with 17-beta hydroxysteroid dehydrogenase 3 deficiency are frequently raised as girls. Approximately half of these individuals will later identify as male during adolescence or early adulthood.

Inheritance:

The inheritance pattern for this condition is autosomal recessive. This means that a person must inherit two copies of the mutated gene, one from each parent, to be affected. The parents, who each carry only one copy of the mutated gene, are usually asymptomatic carriers. Genetically male individuals (XY) with two copies of the mutated gene will manifest 17-beta hydroxysteroid dehydrogenase 3 deficiency. Genetically female individuals (XX) with two mutations typically do not show symptoms of the disorder.