Aromatase deficiency: an unusual cause for primary amenorrhea with virilization

The most common cause for menstrual abnormality and virilization in children and adolescents would be congenital adrenal hyperplasia. An elevated 17(OH) progesterone is invariably seen in this condition. Aromatase deficiency can also lead to a similar presentation but differs in several aspects. The age of onset of the clinical manifestations, the phenotype, biochemical abnormalities and karyotype help us to arrive at a definitive diagnosis. However sometimes the history is atypical, biochemical abnormalities may overlap between the different conditions and prior treatment may modify the clinical features. We report here a young adult with a late presentation of aromatase deficiency to highlight the differences between the two conditions. A 27 year old lady presented to us with history of primary amenorrhea and masculine voice. She lacked feminine secondary sexual characters, had eunuchoid body habitus and prominent clitoromegaly. Consanguinity in the parents, a neonatal sibling death and elevated basal 17(OH) progesterone in the patient suggested a possibility of congenital adrenal hyperplasia. But the eunuchoid body habitus raised FSH and lack of response to dexamethasone led to a diagnosis of aromatase deficiency. Variability in the degree of aromatase deficiency is known such that maternal virilization may not occur in pregnancy. Aromatase deficiency should be suspected when a patient presents with primary amenorrhea, absence of female secondary sexual characters, virilization and tall stature with eunuchoid body proportions, and biochemical features of ovarian failure. In our country one should be aware that late presentation and prior treatment may modify disease expression and contribute to the diagnostic challenge.