Cytogenetic profiles of a large cohort of patients with sexual developmental disorders; A 22-year single-center experience

Abstract

Background Disorders of Sex Development (DSD) are rare and variable disorders that result from abnormalities in karyotype, gonadal formation, androgen synthesis and androgen action. It is important that newborns with gender ambiguity should be evaluated urgently, and then the etiology should be determined by karyotype and hormone analysis. Objective The aim of this study is to determine the frequency and structure of cromosomal abnormalities (CAs) seen in patients with the clinical findings of ambiguous genitalia (AG), hypogonadism (HG), intersex (IS), hypospadias (HS), testicular feminization (TF) and vaginal hypoplasia (VH) between 1990 and 2012. Materials and Methods We investigated 85 patients which referred to our department. For chromosome analysis, peripheral blood samples were cultured, harvested and banded according to standard methods. Results Percentage rates of 117 patients were 53.8%, 27.4%, 8.5%, 5.1%, 3.4% and 1.7%, respectively, having AG, HG, HS, IS, TF and VH irregularities. Of the patients, 64.9% had normal karyotype and 35.1% had abnormal chromosome setup. In 17 (15.3%) of all patients, the phenotypic sex did not match with the genotypic sex (46,XX; 46,XY). Sex-chromosome mismatch chimerism was found in 7 patients (6.0%) (46,XX/46,XY chimeric individuals). Sex chromosome mismatch chimerism was detected in seven patients (5.9%). Sixteen (13.7%) of all patients had mosaicism of the sex chromosomes. Structural abnormalities were found in gonosomal and autosomal chromosomes in 8 patients (6.3%) Conclusion The present date shows that CAs play a role in 38.9% of 85 patients with DSD. Molecular and hormonal techniques may also need to be performed in patients whose genotype-phenotype correlations cannot be made in other patients. It also shows that patients with mosaic cytogenetic findings may actually have chimerism and it is difficult to predict the clinical outcome in these patients.