[Sex differentiation and its anomalies]

Area of Science:

• Reproductive biology
• Endocrinology
• Genetics

Context:

• Sexual development is a complex, sequential process involving genetic, gonadal, phenotypic, and psychological factors.
• Testis determination is the primary event in sex determination, initiating gonad differentiation.
• Hormones critically regulate all subsequent sexual differentiation after gonad development.

Purpose:

• To present a comprehensive classification of abnormal sexual development.
• To delineate errors in primary sex differentiation, including chromosomal anomalies and gonadogenesis issues.
• To describe errors in secondary sexual differentiation, such as inadequate masculinization or virilization.

Summary:

• The authors classify disorders of sexual development based on errors in primary sex differentiation (chromosomes, gonads) and secondary sexual differentiation (hormonal effects).
• Key events include testis determination and gonad differentiation, with hormonal control over subsequent development.
• The classification addresses issues like inadequate masculinization in genetic males and virilization in genetic females.

Impact:

• Provides a framework for understanding and diagnosing disorders of sexual development.
• Highlights the critical roles of genetics and hormones in sexual differentiation.
• Informs the clinical approach to managing patients with intersex conditions.