ESPE2024 Poster Category 1 Sex Endocrinology and Gonads 1 (8 abstracts)
1Dicle University, School of Medicine, Department of Pediatric Endocrinology, Diyarbakir, Turkey. 2Antalya Education and Research Hospital, Department of Medical Genetics, Antalya, Turkey. 3Erzurum Region Education and Research Hospital, Department of Pediatric Endocrinology, Erzurum, Turkey. 4Bakırköy Dr. Sadi Konuk Education and Research Hospital, Department of Pediatric Endocrinology, Istanbul, Turkey. 5Marmara University School of Medicine, Department of Pediatric Endocrinology, Istanbul, Turkey. 6Hacettepe University School of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey
Context: Duplications occurring upstream of the SOX9 gene have been identified in a limited subset of patients with 46,XX testicular/ovotesticular differences/disorders of sex development (DSD). However, comprehensive understanding regarding their clinical presentation and diagnosis is limited.
Objective: To gain further insight into the diagnosis of a large cohort of 46,XX individuals with duplications upstream of SOX9.
Design and Setting: We retrospectively analyzed data of 46,XX/ SRY -negative individuals with SOX9 upstream duplications.
Methods: Clinical data were systematically recorded, and genetic etiologies were investigated through comprehensive methodologies including karyotyping, fluorescence in situ hybridization (FISH) for SRY analysis, gene panel sequencing, multiplex ligation-dependent probe amplification (MLPA), and microarray analysis.
Results: We analyzed twelve 46,XX individuals with heterozygous duplications upstream of SOX9, ranging from 74-955 kb. Ages at diagnosis ranged from 0.1 to 55 years. Seven (58%) had testicular/ovotesticular DSD, while five (41%) were asymptomatic carriers detected through family screening. In three cases, the duplication was paternally inherited, while in two cases, it was inherited from asymptomatic mothers. Duplication missed by 300K microarray in a family was found by MLPA and confirmed by 750K. There was no significant correlation between duplication size and genital/gonadal phenotype.
Conclusion: 46,XX individuals with SOX9 upstream duplications may exhibit no symptoms, but thorough family screening is crucial due to the potential inheritance and subsequent testicular/ovotesticular DSD risk. We emphasize the effectiveness of utilizing high-resolution microarray analysis (>500K) as the primary diagnostic tool for 46,XX/ SRY -negative testicular/ovotesticular DSD patients, enabling thorough genome-wide assessment of copy number variations, detecting small alterations.