Original Article

A novel homozygous CYP19A1 gene mutation: Aromatase deficiency mimicking congenital adrenal hyperplasia in an infant without obvious maternal virilisation

10.4274/jcrpe.0140

  • Fatma Dursun
  • Serdar Ceylaner

Received Date: 24.05.2018 Accepted Date: 02.08.2018 J Clin Res Pediatr Endocrinol 0;0(0):0-0 [e-Pub] PMID: 30074481

Aromatase deficiency is a rare autosomal recessive disorder in which affected patients cannot have a normal estrogen synthesis. Herein, we report a 46, XX patient born with virilised external genitalia. A novel homozygous mutation in the CYP19A1 gene, causing aromatase deficiency, was detected.

A 30-day infant was referred to pediatric endocrinology because of a uterus, detected in an ultrasonography examination. He was born at 23th gestational week with C-section because of preeclampsia and premature membrane rupture. There was not an evidence of virilisation, such as acne, hirsutism, deep voice, clitoris enlargement, in maternal history. Physical examination revealed complete scrotal fusion and a single urogenital meatus, consistent with Prader stage-3. Standard dose ACTH test revealed an inadequate cortisol response and high 17-OH-progesterone levels, suggesting simple virilising congenital adrenal hyperplasia due to 21-hydroxylase deficiency. However no mutation in CYP21A2 gene was detected. At the age of 2.5 years of age we repeated ACTH test after suspension of hydrocortisone treatment for 48 hours. This time, cortisol and androgen levels were normal. The patient was re-evaluated in terms of 46, XX disorder of sex development (DSD), especially with the suspicion of aromatase deficiency. A novel homozygous exon 6 deletion was identified in the CYP19A1 gene.

Aromatase deficiency could easily be confused with congenital adrenal hyperplasia in newborn period. In a case of 46, XX DSD aromatase deficiency can present without the history of maternal virilisation or without large and multycystic ovaries.

Keywords: 46 XX DSD, CYP19A1, aromatase deficiency