Agarose gel electrophoresis of the PCR fragments digested by restriction enzymes. (A) Diagnosis of the C282Y mutation: digestion with Rsa I (lanes 2 through 4) and SnaBI (lanes 7 through 9). For both enzymes a novel restriction site is created by the C282Y mutation. Rsa I has an obligate restriction site in this PCR fragment. Lanes 1 and 6, undigested PCR; lanes 2 and 7: normal control; lanes 3 and 8, heterozygote for the C282Y mutant; lanes 4 and 9, homozygote for the Y282 allele; lanes 5 and 10, 1 kb ladder (GIBCO-BRL [France]). (B) Diagnosis of the H63D mutation: digestion with Fba I (Bcl I); the mutation abolishes the restriction site. Lane 1, normal individual; lane 2, homozygous patient for the H63D substitution; lane 3, heterozygote for the H63D substitution; lane 4, 1-kb ladder (GIBCO-BRL).