Surgical management and molecular diagnosis of persistent Mullerian duct syndrome in Chinese patients

Persistent Mullerian duct syndrome (PMDS) is a rare clinically and genetically overlapping disorder caused by mutations in the anti-Mullerian hormone (AMH) gene or the anti-Mullerian hormone receptor type 2 (AMHR2) gene. Affected individuals present uterus and tubes in normally virilized males and are discovered unexpectedly during other surgeries. Since it is rare and complex, a definitive clinical diagnosis can be missed, and there are no guidelines regarding how to deal with the uterus. In the present study, exome sequencing and Sanger verification were performed for causal variants in 12 PMDS patients. Preoperative diagnoses were made by positive exome sequencing in 8 patients. Of them, 7 patients evoked on the basis of ultrasound indicating bilateral testes on the same side of the body. Twelve different AMH variants (2 frameshift/nonsense, 1 deletion, 8 missense, and 1 in-frame) in 9 patients and 6 different AMHR2 variants (5 missense and 1 splicing) in 3 patients were identified. Seven variants were classified as "pathogenic" or "likely pathogenic", and 4 of them were novel. All but two patients with AMH defects showed low serum AMH concentrations, but all patients with AMHR2 defects showed elevated AMH levels. During surgery, an abnormal vas deferens was observed in half of the patients. Eight patients underwent orchidopexy with uterine preservation. Of them, 2 patients presented complications including irreducible cryptorchidism, and 3 patients developed Mullerian remnant cysts. Three patients underwent subtotal hysterectomy. Of them, one patient had complication of injury to the vas deferens, and one had hemorrhage after operation. This is the first report of PMDS involving a large Chinese population. The present study not only expands the variation spectrum but also provides clinical experience about the management of the uterus.