The ~11 kb deletion silences one
allele in the blood of affected individuals. Germline heterozygous SNPs were evaluated in the RNA isolated from peripheral blood, with sample traces shown here. dbSNP rs465899 was found to be heterozygous in the proband 0124 (III-5) gDNA but not in the cDNA, whereas this SNP was heterozygous in both gDNA and cDNA in the unaffected subject 0124 (III-4). A loss of cDNA heterozygosity was also observed in proband 0130 (IV-1) with SNP rs459552, and in proband 0163 (III-2) with SNP rs465899.