ESPE Abstracts

Background: Disorders of sex development (DSD) are congenital conditions in which chromosomal, and gonadal or anatomical sex is atypical.

Objective and hypotheses: We describe the case of a 46,XX newborn with ambiguous genitalia. 46,XX DSD set in differential diagnosis disorders of gonadal development (ovotesticular DSD, testicular DSD, gonadal dysgenesis), androgen excess of fetal (mainly congenital adrenal hyperplasia due to deficiency of 21-hydroxylase, 11-hydroxylase, and 3β-hydroxysteroid dehydrogenase), fetoplacental (aromatase deficiency) or maternal origin (luteoma and virilizing tumors) and malfomations.

Results: Hormonal tests showed testosterone above normal and cortisol at the lower limit; steroid replacement therapy was started. Search for SRY was negative. Ultrasound revealed two gonads at the external genitalia. The patient was given the female sex. The absence of maternal virilization excluded tumors and aromatase deficiency. The following hormonal investigations documented normal values of gonadotropins, androgens, and cortisol adjusted for age. The absence of adrenal insufficiency excluded forms of congenital adrenal hyperplasia, so glucocorticoid replacement therapy was discontinued. The HCG test showed a poor response of androgens. The patient was subjected to gonadal biopsy with histological diagnosis of bilateral ovotestis.

Conclusion: The ovotesticular DSD is a rare disorder defined by the presence of both ovarian and testicular tissue in the same individual. The structure of the ovary is usually normal, while testicular tissue is immature and histologically abnormal. The development of müllerian and Wolffian derivatives is variable. The external genitalia are ambiguous with various degrees of virilization. The SRY gene in 46,XX ovotesticular patients is present in ~1/3 of the cases. Array-CGH analysis of our patient showed duplication 17q24, which contains SOX9 gene. In embryos XY SRY interacts with SOX9 in the differentiation of the testis. In subjects XX duplication of SOX9 has been described as a cause of 46,XX DSD. The same duplication was present in the father.