Higher CNV frequencies in Chromsome-14 of girls with Turner
Precise genotype-phenotype correlations in Turner syndrome (TS) have not yet been deciphered. The chromosomal basis of the clinical TS-phenotype in the absence of X chromosome aberrations on the conventional karyotyping remains more and less unexplored.

This study aimed to elucidate the high resolution chromosomal picture and analyze the genotype -phenotype associations in girls with clinical phenotype of TS by chromosomal microarray (CMA).

Cross sectional observational study was conducted on 47 girls presenting the clinical TS-phenotype and fulfilling the criteria for chromosomal analysis.

-- The CNV (copy number variation) polymorphs were more frequent on autosomes than X chromosomes and they were detected in 89.3%, 61.7 %, and 92.8 % of patients respectively on chromosome 14 or X or both.

-- Total 445 and 64 CNV polymorphs were discovered on chromosome X and 14 respectively.

-- The latter exhibiting either gain at 14q32.33 or loss at 14q11.2 or both. Karyotype was available for 27 patients; 55.6% cases displayed X chromosome abnormalities while 44.4% cases had a normal karyotype.

-- Functional interactomes of the genes those were present in Chromosome 14 CNVs and those known to be associated with TS showed an overlap of 67% and enriched various development-related cellular pathways underlying TS-phenotype.

Conclusively, on high resolution karyotype analysis, clinical phenotype of TS could be found associated with CNV defects in autosomes (specifically Chr. 14,) or X chromosome or both. The syndrome of chromosome 14 CNVs defects with and without X-chromosomal defects clinically mimics TS and shares a common genomic network deserves further investigations.

Source: https://academic.oup.com/jcem/advance-article-abstract/doi/10.1210/clinem/dgab572/6333386?redirectedFrom=fulltext