Aromatase Deficiency due to a Novel Mutation in CYP19A1 Gene.

BACKGROUND: Aromatase deficiency is a rare autosomal recessive genetic disorder with an unknown incidence. Aromatase converts androgens into estrogen in the gonadal and extra-gonadal tissues. Aromatase deficiency causes ambiguous genitalia in the female fetus and maternal virilization (hirsutism, acne, cliteromegaly, deep voice) during the pregnancy due to increased concentration of androgens.

METHODS AND RESULTS: The-nineteen-month-old girl was assessed due to ambiguous genitalia There were findings of maternal virilization during pregnancy. The karyotype was 46, XX. Congenital adrenal hyperplasia (CAH) was not considered since adrenocorticotropic hormone (ACTH), cortisol, and 17-hydroxyprogesterone (17-OHP) levels were within normal ranges. follicle-stimulating hormone (FSH) and total testosterone were elevated and estradiol was low when she was two months old. Depending on these findings, aromatase deficiency was considered. A novel homozygous mutation (IVS7-2A>G[c.744-2A>G]) was identified in the CYP19A1 gene. Pelvic ultrasound showed hypoplasic ovaries rather than large and cystic ovaries.

CONCLUSION: We identified a novel mutation in the CYP19A1 gene in a patient who presented with ambiguous genitalia and maternal virilization during pregnancy. Presence of large and cystic ovaries is not essential in aromatase deficiency. Key words: aromatase deficiency, CYP19A1 gene, maternal virilization, ambiguous genitalia.