Abstract: Objective: To increase the knowledge on disorders of sex development (DSD) caused by DMRT1 haploinsufficiency. Methods: Clinical features in a patient with 46XY DSD were described. Peripheral lymphocytic karyotype was measured in this patient and her parents. Furthermore, array comparative genomic hybridization (aCGH) was done to the patient. Results: (1) Clinical features: the patient presented with female genital, and neither uterus nor ovaries were detected by B ultrasound. Mental and physical development retardation was observed, consisted with the manifestation of 9p deletion syndrome. (2) Karyotype: Her mother was 46XX,t(7;9)(q35,p24); Her father was 46XY; The patient was 46XY, der(9) t(7;9) (q35,p24); (3) aCGH scan: 14.37Mb triplication was fond in the terminal of 7q (144741153-159098761); 9.72Mb deletion was found in the terminal of 9p (10001-9733061), containing the following genes, EZH2, MNX1, DMRT1, DMRT2, SHH, SMARCA2, GLDC, VLDLR, DOCK8 and GLIS3; Conclusions: DMRT1 gene plays an essential role in gonadal development. Haploinsufficiency in this gene may result in testicular dysplasia and DSD.

Key words: Chromosome 9, Disorders of sex development, DMRT1 gene, Haploinsufficiency