Clinical and laboratory findings evaluation of patients with sex development disorders

Background: Disorders of sex development (DSD) are defined as congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. The aim of our study is to evaluate patients followed with a diagnosis of gender development disorder (GDD) in our clinic in terms of clinical, laboratory, radiological, pathological and genetic aspects and to present their follow-ups with a multi-disciplinary approach. Materials and methods: The files of the cases diagnosed with DSD between 1987 and 2019 in the Outpatient Clinic of Istanbul University, Istanbul Faculty of Medicine, Department of Pediatrics, Growth-Development and Pediatric Endocrinology were retrospectively reviewed. The cases' ages of application, the identity at which they were raised at the application, their background characteristics, family history characteristics, anthropometric measurements, physical examination findings, laboratory results, radiological imaging, genetic analysis results and pathology findings were examined from their polyclinic file information. The cases were divided into three groups according to Chicago Classification as 46, XX DSD, 46, XY DSD and genus chromosome DSD. Results: As a result of the etiological classification of 518 cases who presented with DSD; 150 (28,96%) were found to have sex chromosome DSD, 167 (32,24%) were found to have 46, XX DSD and 201 (38,8%) were found to have 46, XY DSD. When the sex chromosome DSD was evaluated, Turner Syndrome (TS) and variants were found in 50.67%, mixed gonadal dysgenesis (MGD) in 30%, Klinefelter Syndrome (KS) and variants in 19.33%. 46, XX DSD were evaluated etiologically, 94,01 % were diagnosed with androgen excess [congenital adrenal hyperplasia (CAH) and most often 80,24% with 21-hydroxylase deficiency], 3,59% were diagnosed with gonadal dysgenesis, 2,4% were diagnosed with mullerian agenesis and others. The etiologies of 46, XY DSD were evaluated, 46,77% were diagnosed with androgen insensitivity syndrome, 31,34% androgen synthesis defect, 18,41% were diagnosed with gonadal dysgenesis and 3,48% were diagnosed with other reasons. Mutation could be shown in 69.23% of complete androgen insensitivity syndrome (CAIS) cases and in 28.57% of partial androgen insensitivity syndrome (PAIS) cases. Conclusions: In our study, 46, XY DSD were found most frequently, then 46, XX DSD, and finally sex chromosome DSD. In the vast majority of 46, XX DSD cases CAH takes place, and 21-hydroxylase deficiency is the most common cause of CAH. This shows the importance of evaluating the cases presenting with suspicious genital structure in the neonatal period from this perspective. It was determined that the majority of 46, XY CGB cases were androgen insensitivity cases. Despite today's advancing technology, the genetic origin of a significant portion of 46, XY CGB cannot be determined. Keywords: Disorders of sex development, suspicious genitalia, 46, XX DSD, 46, XY DSD, sex chromosome DSD.