VSC/DSD identification: introduction

Variations of Sex Characteristics (VSCs)/Differences of Sex Development (DSDs) can be diagnosed prenatally, for example, if there is an altered number of chromosomes (such as the presence of a supernumerary or excess chromosome) or a mismatch between the result of amniocentesis and the morphological features detected by ultrasound. VSCs/DSDs may also be identified at birth, when genital characters are non-attributable to those typically considered male or female (atypical genitalia). In these cases, further medical investigation is needed to assign a gender to the infant. At times, variations become evident only later on, often during puberty, from a missed, delayed or unexpected pubertal development – in the latter case, the appearance of mammary development in a person assigned male at birth (AMAB) or the lowering of voice timbre along with hair development in a person assigned female at birth (AFAB). A VSC/DSD may also be detected in adulthood because of infertility or deficient hormone production.

It is crucial to emphasize that before undertaking any procedure, including diagnostic evaluation, the patient, or their parents and/or legal guardians must be thoroughly informed by the medical team and give their consent, always respecting the person's decision-making capacity if sensitive and/or invasive procedures are involved.

The diagnostic evaluation includes a complete physical examination, biochemical and genetic tests, as well as imaging studies (e.g., ultrasound and MRI).