Chromosomal microarray analysis is a first-stage test that is used for the diagnosis of intellectual disability and global developmental delay. Chromosomal microarray analysis can detect well-known microdeletion syndromes. It also contributes to the identification of genes that are responsible for the phenotypes in the new copy number variations. Chromosomal microarray analysis was conducted on 124 patients with intellectual disability and global developmental delay. Multiplex ligation-dependent probe amplification was used for the confirmation of chromosome 22q11.2 deletion/duplication. 26 pathogenic and likely pathogenic copy number variations were detected in 23 patients (18.55%) in a group of 124 Turkish patients with intellectual disability and global developmental delay. Chromosomal microarray analysis revealed pathogenic de novo Copy number variations, such as a novel 2.9-Mb de novo deletion at 18q22 region with intellectual disability and autism spectrum disorder, and a 22q11.2 region homozygote duplication with new clinical features. Our data expand the spectrum of 22q11.2 region mutations, reveal new loci responsible from autism spectrum disorder and provide new insights into the genotype–phenotype correlations of intellectual disability and global developmental delay.

Objectives: Hereditary breast and ovarian cancer syndrome is chacterized with multiple cases of breast cancer and/or ovarian cancer on the same side of the family. BRCA1/BRCA2 genes are associated with 20–25% of all patients. For developing national health policies for genetic testing, it is important to determine the range of pathogenic mutations in susceptibility genes and to identify recurrent founder mutations. Materials and methods: All the patients were provided BRCA testing criteria according to National Comprehensive Cancer Network. QIAseq multiplex amplicon panel, BRCA MASTR™ Dx and Ion AmpliSeq Panel were used for BRCA1/BRCA2 coding regions. SALSA ^® MLPA ^® was performed for negative patients. Results: Of 1419 patients, 134 (9.4%) were found to carry a pathogenic and 5 (0.3%) were found to carry a likely pathogenic mutation. Of those, 58 patients were found to carry a mutation in BRCA1 and 64 in BRCA2. Variant of uncertain significance was detected in 91 patients (6.4%). Conclusion: The spectrum of BRCA1/2 mutations in Turkish population has been shown in the largest patient group to date. The thesis that founder mutations show diversity in different populations has been confirmed in our study, and the mutations that are common in Turkish population have been presented in this study.