For GLD1, sequencing libraries were made following the protocol from Roche/Nimblegen’s SeqCap EZ Exome Library v2.0 kit (Roche NimbleGen, Inc). The libraries were then sequenced on a HiSeq2000 (Illumina), with paired-end, 101bp reads. For GLD2 and GLD3, whole exome capture was performed using the SureSelect Target Enrichment System (Agilent). This was followed by sequencing on a HiSeq2000 (Illumina) with 100bp paired end reads. Sequence reads for all families were aligned to the reference genome (hg19) using Novoalign (Novocraft Technologies SdnBhd). Duplicate reads, resulting from PCR clonality or optical duplicates, and reads mapping to multiple locations were excluded from downstream analysis. Depth and breadth of sequence coverage were calculated with custom scripts and the BedTools package26 (link).