[Association of mixed gonadal dysgenesis and non-classic 21-hydroxylase deficiency].

BACKGROUND

The rare association of mixed gonadal dysgenesis and non classical congenital hyperplasia by 21-hydroxylase deficiency poses the problem of their respective responsibility in the development of sexual ambiguity.

METHODS

In a newborn with ambiguous genitalia, blood 17-OH progesterone was moderately elevated (3.9 to 14.1 ng/mL) leading to the diagnosis of non-classical 21 hydroxylase deficiency, Molecular studies later confirmed this diagnosis. However, the presence of a palpable gonad and the karyotype (45 X/46 XY mosaicism) indicated a mixed gonadal dysgenesis as the cause of sexual ambiguity. Histological examination revealed the presence of a testis and a streak gonad.

CONCLUSIONS

This observation emphasizes the need for a complete clinical and biological analysis in all newborns with sexual ambiguity.