(a) Pedigree drawing of the FHC family carrying the ACTC Ala295Ser mutation. Individual numbers are given in italics, and symbols are defined as follows: squares, men; circles, women; diagonal slashes, deceased; open symbols, unaffected individuals; filled symbols, affected individuals fulfilling major diagnostic criteria; shaded symbols, affected individuals fulfilling minor diagnostic criteria; hatched symbols, excluded from linkage analyses because of hypertension. Alleles defined by the STR polymorphism within ACTC are shown in roman numerals (16). Thin bars indicate normal genotype of ACTC; thick bars indicate ACTC mutation segregating with allele 2. The genotype of individual I-3 was inferred from offspring. Individuals II-3 and II-8 have 2 children each who did not want to participate in this investigation. This may well influence the otherwise surprising observation that all individuals of the third generation carry the mutant allele. (b) Sequence of the ACTC wild-type and the G253→T mutated allele.