Validation of mutations in RBCK1 in two families. (a,b) Validation on the nonsense mutation and frameshift indel in family 1. The identified mutations are labeled with arrows. The nucleotide sequences of the insertion were resolved from the sequence trace. (c) SNP array showed a 1.2 Mb copy-neutral region-of-homozygosity (ROH) on chromosome 20p in the proband from family 2. The upper panel (log R ratio) represents normalized total signal intensity, demonstrating the lack of copy number changes in the 1.2 Mb region. The lower panel (B allele frequency) represents normalized allelic intensity ratio, demonstrating the lack of heterozygous SNPs in the 1.2 Mb region. The location of RBCK1 is marked by the grey vertical line. (d,e) Validation of a homozygous intronic variant and a homozygous splice variant in the proband from family 2.