New genomic technologies: an aid for diagnosis of disorders of sex development

The Chicago Consensus Conference of 2005 defined Disorders of Sex Development (DSD) as "congenital conditions in which the development of chromosomal, gonadal or anatomic sex is atypical." DSD diagnoses are difficult to establish. A lack of standardization of anatomical and endocrine phenotyping and the limited number of known DSD genes and genotype/correlation has long hampered the field, leaving many patients without a definitive diagnosis. The resulting uncertainty may intrinsically pose a great amount of discomfort to affected individuals and their families. DSD-causative genes have historically been identified thanks to positional cloning of disease-associated variants segregating in families or chromosomal rearrangements. Recent advances of chromosomal microarray and exome sequencing technologies are allowing for higher rates of diagnostic success for DSD patients and are changing clinical practice. In this review, we discuss the application of these technologies and their findings as an upcoming model for clinical diagnosis of DSD. We show that exome sequencing is a valuable tool and we propose that it should be used as a first-stage diagnostic technique because it allows for early identification of a genetic cause that may be critical for patient management.