Figure 3

Haplotypes and restriction fragment polymorphism (RFLP). Haplotypes were analysed using the markers surrounding CCM1 as described in Methods. The markers from top to bottom were: D7S2409, D7S1813, D7S1789, D7S646, D7S558, D7S689, D7S652 and D7S492. Exon 17 was amplified with the primers and aliquots of the PCR were digested overnight at 37°C with MseI. The fragments were separated in an 8% polyacrylamide gel containing urea and, after staining with ethidium bromide, the gel was photographed under UV. The undigested product is 297 pb long and the fragments separated from the TTAA restriction site are 158 and 139 pb. Therefore, individuals harbouring the 1902insA mutation have three fragments of 297, 158 and 139 bp. Filled symbols in the pedigree refer to patients with CCMs in the echo-gradient MRIs. Arrow indicates the proband. Stairs refer to asymptomatic carriers of the mutation. The double stair denotes the asymptomatic carrier with MRIs free of CCMs