[Phenotypic and molecular characterizations of 46,XY disorders of sex development due to variants of NR5A1 gene].

Objective: The clinical and molecular genetic characteristics of 46,XY disorders of sex development caused by NR5A1 gene variants in 15 cases were analyzed to improve the understanding of this disease.

Methods: The clinical data of children with NR5A1 gene variants diagnosed at the Children's Hospital Affiliated to Zhengzhou University from March 2016 to December 2021 were retrospectively analyzed. Whole exome sequencing was performed to confirm the candidate sites, and Sanger sequencing was performed for validation. The patients were treated and followed up according to their disease characteristics.

Results: At the initial diagnosis, 5 of the 15 cases were raised as females and 10 as males. The gonadal tissue was testis without residual Müllerian or ooticular structure, and all had various degrees of genital abnormalities. The average EMS masculinity score was 4.8 (1 ~ 9), including micropenis (100.0%), hypospadias (86.7%), unfused scrotum (46.7%), and abnormal testicular position (60.0%), in which the hypospadias was Ⅱ°~ Ⅳ°. There was no skin pigmentation in 5 patients with growth retardation. Chromosomal karyotypes were 46,XY, adrenocorticotropin and cortisol levels were normal, electrolyte levels were normal, HCG stimulation test in 5 cases had normal response, 9 cases had low response. Anti-Müllerian hormone and statin B had decreased abnormally with age. A total of 14 NR5A1 variants were detected in the 15 children, most of which occurred in exon 4, of which 9 variant loci were not included in the HGMD database as of December 2022.

Conclusion: The clinical phenotype of 46,XY abnormal sexual development caused by NR5A1 gene variants is extensive, with the external genitals showing varying degrees of insufficient masculinization. Adrenal involvement is rare.