2.3 Genome sequencing
GS was performed by Berry Genomics (Beijing, China). The DNA of the affected families was isolated from peripheral blood using the QIAamp DNA Mini Kit (QIAGEN, Hilden, Germany). Library preparation was performed using TruSeq DNA PCR-Free Library Prep Kit (Illumina, San Diego, CA, USA) following the manufacturer’s protocol. The prepared libraries were sequenced on a NovaSeq 6000 (Illumina) to generate 150bp paired end reads. The average depth was approximately 40X.