Abstract 46: Karyotype and phenotype correlation in Turner syndrome in South India

Background: Phenotypic and karyotypic features of Turner syndrome (TS) varies significantly which leads to challenges for the clinicians in diagnosis and management. There are only few committed studies from India regarding TS. This current study analyzes karyotype – phenotype differences among patients with TS. Objectives: To assess the correlation between karyotype and phenotypic features in patients with TS. Methods: This is a cross sectional study of 10 patients diagnosed with Turner syndrome (Jan 2021–Nov 2021). These patients were divided into 4 groups according to their karyotype: Classic (45X, Mosaics (45,X/46,XX), IsochromosomeXq (46,X,iXq and 45,X/46,X,iXq mosaics), others (45,X/46,XY mosaics and structural defects), and analyzed for various phenotypic features. Results: Majority (40%) had classic karyotype followed by mosaic Turner (30%), isochromosomeXq (20%). Age at diagnosis was 16.7 ± 2.5 years, with 8 girls were adolescence and 2 were adult at diagnosis. Short stature and delayed puberty were the most common presenting feature (100%). Cardiac anamoly and renal anamoly were most commonly seen in classic TS (1/10, 10%). Subclinical hypothyroidism (SCH) occurred in patient with classic Turner (1/4, 25%) and patient with isochromosomeXq (1/2, 50%). Conclusion: A significant proportion of girls presented with short stature and or delayed puberty have TS. Phenotypic features including renal malformations, cardiac disease, and dysmorphic features are more prevalent in Classic TS and correlated with degree of X chromosome loss. Thyroid disorders were more common in TS with isochromosomeXq. Mean age at diagnosis of TS is relatively late, a situation which could be improved by providing appropriate awareness among general practitioners and school teachers.