Identification of the missense mutation in exon 7 of the b5R gene by PCR/restriction analysis.

(A) Diagram of genomic restriction enzyme analysis. The 262-bp genomic fragment of exon 7 was amplified. The mutated allele possesses an additional RsaI site and produces 3 fragments (3 bp, 125 bp, 134 bp) upon digestion. (B) Restriction enzyme analysis. The 262-bp genomic PCR fragments from the propositus, some of her family members, and a normal control were digested with RsaI and electrophoresed on 12% polyacrylamide gel. The 2 visible products of digestion are indicated by arrows. The DNA markers used areBsuRI digests of pBR322 (MBI). N1 and N2 indicate the PCR products of the normal control after and before digestion, respectively.