46,XY DSD: Testosterone Biosynthesis and Androgen-Receptor Action Quiz

46,XY DSD (Disorders of Sex Development)

• Undervirilized males or phenotypic females in 46,XY DSD are primarily caused by androgen insensitivity or defects in androgen production and action.

hCG/LH Receptor Abnormalities

• Abnormalities in hCG/LH receptors within the testes can lead to impaired testosterone production and insufficient differentiation of male genitalia.

AMH and AMH Receptor Deficiencies

• Defects in Anti-Müllerian Hormone (AMH) and its receptors result in persistent Müllerian duct syndrome, leading to the presence of female reproductive structures in genetically male individuals.

Androgen Receptor Defects

• Defects in the androgen receptor can cause varying degrees of androgen insensitivity, resulting in phenotypic females despite a 46,XY karyotype.

Peripheral Defects in 46,XY DSD

• Peripheral defects may involve issues in adrenal steroidogenesis or transport, affecting overall hormone levels and leading to atypical genital development.

Leydig Cell Hypoplasia

• 17β-Hydroxysteroid dehydrogenase deficiency can lead to Leydig cell hypoplasia, contributing to reduced testosterone synthesis.

Outcome of AMH and AMH Receptor Disorders

• Disorders of AMH and its receptor can lead to male individuals having female or ambiguous genitalia due to failure of Müllerian duct regression.

Complete Androgen-Insensitivity Syndrome (CAIS)

• Individuals with CAIS typically present as females with well-developed external female genitalia and secondary sexual characteristics, despite having XY chromosomes.

Abnormalities in Androgen Receptor Action

• Abnormalities can result in a spectrum of conditions from complete insensitivity to partial androgen sensitivity, influencing genital and secondary sexual development.