Exome Sequencing

Genomic DNA from the peripheral blood lymphocytes of the patients and their family numbers was extracted with a Lab-Aid DNA kit (Zeesan Biotech Co., Ltd, Xiamen, China). The DNA concentration and purity were determined using a NanoDrop ND-2000 ultraviolet spectrophotometer and software (Thermo Fisher Scientific, Waltham, MA). For exome sequencing, the library was prepared using an Agilent SureSelect Human All Exon V6 Kit (Agilent Technologies, Santa Clara, CA). The complete libraries were then sequenced on a HiSeq2500 system (Illumina, San Diego, CA). Sequence alignment and variant calling against the human GRCh37 reference genome were performed using BWA and the Genome Analysis Toolkit (GATK HaplotypeCaller). The analysis of copy number variants (CNVs) was processed on an in-house pipeline, and CNVs of significant interest were further visually inspected using the Integrative Genomics Viewer. Single nucleotide variants and indels were filtered and prioritized with TGex software (LifeMap Sciences, Alameda, CA). All operations were performed according to the manufacturer's instructions.