Confirmation: A crucial step in copy number variation analysis after exome sequencing in intellectual disabilities

Abstract

Intellectual disability (ID) comprises a group of mental disorders which have underlying genetic causes, among which the monogenic causes are one of the causes for ID. One kind of a monogenic cause is the copy number variations (CNVs). These CNVs can be indicated using exome sequencing (ES) and the CoNVex and CoNIFER algorithms. To confirm the possible causative CNVs quantitative PCR (QPCR) was used. In a Pakistani ID patient a homozygous deletion of ENTPD3 was indicated and in an Estonian ID patient CPVL-CHN2 a homozygous duplication was indicated. However the QPCR showed that ENTPD3 did not segregate and CPVL-CHN2 was only duplicated heterozygous. Confirmation, like QPCR, is therefore a crucial step in confirming CNVs analysis of ES in ID patients.