A Prospective Screening of Gene Copy Number Variation in Brazilian Admixed Population Sample

Copy number variants (CNVs) represent an important source of variation in the human genome. Some CNVS embedded genes are differently distributed among the human population groups. Therefore, it is important to understand the distribution of CNV within and between populations, especially in those with admixed ancestry, such as the Brazilians. The aim of the study was to investigate the variability of a set of CNV-embedded genes in a sample of the Brazilian population. The CNV-embedded genes were chosen based on data showing that they have differential copy variation distribution between African and Europeans. Four genes (POLR2J4, PCDHB13, NPEPPS and AMY1) were investigated by qPCR in a sample of 96 Brazilians, previously classified by genetic ancestry. The gene AMY1 showed a variable copy numbers in the range of 1 to 8 copies whereas NPEPPS ranged from 1 to 5 copies. A low variability was identified for the POLR2J4 and PCDHB13 genes, showing 2 copies in frequency of 0.875 and 0.917, respectively. Genetic ancestry was not correlated to the number of copies of the AMY1and NPEPPS genes. The results provided an overview of the corresponding frequency of gene copy number variation in a sample of the Brazilian population, serving as reference for further genetic population studies, which may correlate these polymorphisms with other phenotypic features.