DNA seq
Whole-exome sequencing was performed using the Truseq Capture Exome Kit (Illumina) which covers around 45 Mb of exonic content. The captured and amplified library was sequenced on the Illumina Nextseq500 platform according to the manufacturers protocol. Paired-end sequences were obtained at a read length of 150 bps. Sequence reads were then aligned to the reference human genome (hg19) using BWA aligner. Alignments then underwent preprocessing steps by PCR duplicates removal, base quality recalibration and realignment around indels. The variants were called by GATK (Genome Analysis Toolkit and annotated by ANNOVAR (http://annovar.openbioinformatics.org/)  Nonsense, frameshift, nonsynonymous and splicesite variants were prioritized by excluding variants with minor allele frequency of >0.01 in gnomAD (https ://gnomad.broadinstitute.org), PopFreqMax databases, by our inhouse exome database and by excluding variants predicted to be benign by variant effect predictor tools such as PolyPhen2 (http://genetics.bwh.harvard.edu/pph2/) and SIFT (http://sift.jcvi.org/). Copy  number  variations  were  called  from  the  exome  data  using  XHMM  software  (https  ://atgu.mgh.harvard.edu/xhmm/).