Disorders of sex development (DSD) are rare disorders occurring when there is a discordance between chromosomal, gonadal, or phenotypic sex. These occur in the presence of genetic mutations that affect one of the two major processes in sex determination or sex differentiation, sex development. In sex determination, the biopotential gonad is genetically programmed based on the sex chromosome complement to become either a testis or ovary. Sex differentiation occurs in the presence of a formed testis or ovary, and is dependent upon the ability of the gonad to produce hormonal factors and/or the presence of the appropriate receptors in extragonadal tissues.