ESPE Abstracts

Background: The persistent Müllerian duct syndrome (PMDS) is a rare 46-XY disorder of sex development, characterized by the persistence of Müllerian derivatives (uterus, Fallopian tubes) in otherwise normally virilised males. The condition is transmitted as a recessive autosomal trait and is caused in most cases by a defect in either the anti-Müllerian hormone (AMH) or the AMH type-II receptor (AMHR-II) genes.

Case report: We present a 9 years old male who was born with bilateral cryptorchidism, scrotum hypoplasia and normal penis. There were no relevant conditions in his familiar (no consanguinity), or personal history. Blood karyotype showed normal result (46 XY; SRY+). Two beta-hCG stimulation tests (1000 U×3 doses) were performed. First at 2.3 years of age (Testosterone post-hCG=150 ng/dl) and then at 8.9 years (Testosterone post-hCG=15.8 ng/dl; normal values >200 ng/dl). Basal AMH was also low (3.1 ng/ml (44–173 mg/dl)). Postnatal ultrasonography detected a tubular-shaped structure close to the urinary-bladder. Laparoscopy was performed at the age of 9. Structures resembling rudimental uterus and Fallopian ducts were found behind the urinary-bladder and were resected. The histological- inmunohistochemistry examination confirmed the müllerian origin of both structures. No gonad tissue was found with the exception of epididymis tissue. Karyotype was performed in both structures with a normal 46-XY result. Sequencing of the AMHR-II confirmed compound heterozygosity. One of the mutations was the recurrent 27 bp deletion in exon 10th. The other was a c.6101 C>T (p.Arg423Cys), in the intracellular serine/threonine kinase domain of the receptor. This mutation is described for the first time.

Conclusion: We present a case of PMDS caused by a mutation in AMHR-II. The association with anorchia is occasionally seen, and is thought to be caused by the increased risk of torsion and subsequent degeneration of the testes. In this patient we hypothesize that the testicular degeneration occurred in the first years of life.