These included a pathogenic variant in KCNQ2 that causes early infantile epileptic encephalopathy and protein truncating variants in MSH2 and MSH6 that confer a very high risk of colorectal cancer.27, 28 A rare pathogenic variant in ABCC8 that causes congenital hyperinsulinism was incorrectly genotyped as homozygous in 43% (9/21) of individuals.29 Overall, 95% (20/21) of people investigated had a least one false positive rare pathogenic variant compared with sequencing. Here, MSH2 is linked to infantile epileptic encephalopathy.