Persistent Müllerian duct syndrome (PMDS) is a rare form of male 46,XY disorder of sex development characterized by failure of Müllerian duct to regress in a male fetus during embryonic development. Approximately 45% of cases with PMDS are due to AMH deficiency (type 1), while 40% of cases are due to receptor defects (type 2). We report a novel mutation in AMHR2 gene in two siblings who presented with bilateral undescended testis.
A 4-year-old boy presented with bilateral undescended testis. At physical examination, the right testis was palpated in the inguinal canal, while the left testis could not be palpated. External genitalia were phenotypically normal male. Ultrasonography revealed absence of left testis and atrophy of right testis. Testosterone response to β-HCG stimulation test was positive. Laparoscopy demonstrated the right testis in the inguinal canal, the left testis behind the urinary bladder, in addition to uterus behind the urinary bladder. His 2-year-old brother also presented with right undescended testis. At physical examination, the right testis could not be palpated and the left testis was palpated in the inguinal canal. External genitalia was phenotypically normal. During surgery, rudimentary uterus was identified between intraabdominal testes. Presence of Müllerian duct structures in cases with karyotype 46,XY confirmed the diagnosis of PMDS. There was second cousin marriage between parents of cases. Homozygous p.V458L(c.1372G>T) mutation in AMHR2 gene was found.
We report a novel mutation in AMHR2 gene as a cause of PMDS. PMDS is a rare condition; however, it must be considered in the differential diagnosis of cryptorchidism with normal male genitalia.