46,XX DSD: Developmental, Clinical and Genetic Aspects

Area of Science:

• Endocrinology
• Genetics
• Developmental Biology

Background:

• Differences in sex development (DSD) in 46,XX individuals result from fetal or postnatal androgen excess.
• Diagnosis typically occurs at birth due to ambiguous genitalia or later through virilization, particularly at puberty.

Purpose of the Study:

• To review key data on normal and abnormal adrenal and gonadal development in 46,XX DSD patients.
• To correlate this knowledge with clinical utility and diagnostic approaches.

Main Methods:

• Review of prenatal development, molecular pathways, and genetic factors in sex development.
• Description of physical, imaging, hormonal, and genetic evaluation strategies for DSD patients, focusing on the 46,XX karyotype.

Main Results:

• Congenital adrenal hyperplasia (CAH) due to enzyme deficiencies accounts for 95% of 46,XX DSD etiologies.
• Genetic abnormalities in genital system development explain other cases.
• Significant phenotypic variability exists, emphasizing the importance of early sign recognition.

Conclusions:

• Understanding the molecular etiopathogenesis of gonadal and adrenal structures is vital for DSD diagnosis and therapy.
• Early identification of subtle signs in the neonatal period can significantly impact prognosis and quality of life for 46,XX DSD patients.