Cytogenetic and Molecular Genetic Investigations in DSD

An early confirmation of the genetic sex in DSDs is the key to its diagnosis and management. Genetic diagnosis of DSDs requires consideration of causes and undestanding sequential processes of normal sex development and differentiation. Karyotyping results are the first and most defining, therefore, mandatory genetic test and help classify the three major DSD subclasses. The involved principal genes are classified as Testicular promoting genes (SOX3, SOX9, FGF9, PGD2) and Ovarian promoting genes (DAX1, WNT4, FOXL2, RSPO1, and β-catenin). Considering the wide and varied spectrum of DSDs, success in ascertaining a genetic cause in XY DSD remains challenging. The standard approach in genetic evaluation of children with DSDs should be to first determine the genetic constitution followed by determining the affected genes.