A novel mutation of anti-Mullerian hormone gene in Persistent Mullerian Duct Syndrome presented with bilateral cryptorchidism: a case report.

BACKGROUND

We report a novel mutation in a case of Persistent Mullerian Duct Syndrome (PMDS). PMDS is characterized by the persistence of female reproductive organs derivatives in a 46,XY subject due to the failure of the Mullerian duct to regress in utero. To date, 53 different mutations of the anti-Mullerian hormone (AMH) gene, including the present one, have been identified.

CLINICAL CASE: A 2-week-old male presented with bilateral cryptorchidism and normal male external genitalia. His karyotype was 46,XY. hCG stimulation test was normal. At age 1 year and 4 months, he underwent laparoscopic surgery which revealed a uterus and fallopian tubes. The anti-Mullerian hormone (AMH) level was undetectable (<0.01 ng/mL). Diagnosis of Persistent Mullerian Duct Syndrome, probably due to an AMH mutation, was made.

GENETIC STUDIES: A unique homozygous T to G base substitution was found at position 2219, near the middle of the exon 5, changing codon CTG to CGG in anti-Mullerian hormone (AMH) gene. This mutation causes leucine to be converted to arginine at position 426 belonging to a (L)RA(L)LLLKALQ highly conserved sequence in the AMH gene. Both parents are heterozygous for the mutation.

CONCLUSION

Persistent Mullerian Duct Syndrome (PMDS) is a rare cause of bilateral cryptorchidism, when in doubt the existence of Mullerian derivatives should be explored by laparoscopy. Assay of serum AMH helps to distinguish between mutations of AMH and AMH receptor. If serum AMH is very low or undetectable, sequencing of the AMH gene usually confirms the presence of a mutation.