Exome Sequencing for Genetic Variant Analysis

Blood was taken for genetic testing in both patients with informed consent. Sequencing of exons 1 and 9–13 of the MAPT gene was performed initially. Subsequently both samples underwent exome sequencing. Exome enrichment was performed using TruSeq Exome Capture kit (Illumina, San Diego, CA, USA). Sequencing was performed on a HiSeq 2000 (Illumina). Reads were aligned to GRCh37/hg19 using BWA, variants called according to GATK best practice guidelines and annotated with ANNOVAR (Wang et al., 2010 (link)). In silico pathogenicity predictions of nonsynonymous variants were done with the combined annotation-dependent depletion (CADD) (Kircher et al., 2014 (link)). Variants were filtered against population databases (1000Genomes, ESP, and gnomAD) and assessed based on variant type (missense, nonsense, splice site, frameshift, nonframeshift) and predicted pathogenicity.