Detection of copy number changes by microarray study in cases followed up with the diagnosis of 45X0 with Turner syndrome and its association with clinical variations
Project no. 20851 · Status: Kapanmış · 2020
Summary
Turner Syndrome (TS) is one of the most common chromosomal abnormalities, with an incidence of approximately one in 2500 live births. Short stature and primary ovarian incuficiency are the two most important characteristic findings of TS. Webbed neck, low set hairline, cubitus valgus are other characteristic features of TS cases. Cases may have severe cardiac and renal anomalies. And they are more risky in terms of autoimmunity and type 2 diabetes than the normal population. The karyotype can vary that include monosomy X, mosaic structure and X chromosome structural anomalies. Genotypic and phenotypic characteristics differ between cases. Objective: This study aimed to correlate the clinical variations seen in TS cases with possible copy number changes that can be detected by microarray study. Materials and methods: Fifty three patients diagnosed with TS, between the ages of 0-18 who were followed up in Ege University Pediatric Genetic Diseases and Pediatric Endocrinology Departments between December 2018 and May 2020 were included in the study. Blood samples were taken from 36 of these cases for microarray study. Results: Karyotypes were as follows; thirty-three of cases were 45,X, 7 were 45,X/46,XX, 6 were 45,X/46,Xi(Xq), 2 were 46,Xi(Xq), 2 were 45,X/46,r(X), one was 45,X/46,Xi(Xp), one was 45,X/46,XY, and one was 45,X/46,X+mar(idicY) karyotype. İn this study the most common clinical finding in TS cases was short stature with a 90% incidence. İnverted nipple was the second most common finding with an incidence of 71.1%. Consistent with the literature, cardiac anomalies were detected in 22 (41.5%) of cases, and the most common was bicuspit aortic valve anomaly. Renal anomaly was found in 14 (26.4%) of cases, and the most common was horseshoe kidney anomaly. Unlike the literature there was no statistically significant relationship between these two major clinical findings and the karyotype results of the cases. A significant correlation was found between karyotype groups and FSH values of the cases (p=0.034). İn monosomy X and mosaic isochromosome Xq cases, the FSH value was found to be significantly higher than those with 45,X/46,XX mosaic karyotype. Copy number variations were found in 8 out of 36 cases whose microarray study was performed. Conclusion: Copy number changes were detected in 8 patients with unexpected atipycal findings. In order to explain the genotype-phenotype relationships in TS, which has a wide range of clinical findings, microarray analysis is recommended in cases with atypical findings.