Figure 12. Pedigree of an HCM positive family from the BA HCM Study. A pathogenic mutation in MYH7 exon 23 (Glu927Lys) was detected in the proband II-4. Echo screening of all siblings was undertaken, and sister II-10 was found to have an interventricular septal measurement of 14 mm. Genetic screening of all family members excluded HCM diagnosis for the sister (II-10). However, the symptom free and echo clear son of the proband, was positive for the mutation and therefore given a pre-symptomatic diagnosis of HCM at the age of 12 years. Symbols in white represent unaffected individuals, in black are individuals with HCM based on clinical or genetic findings, and in blue are individuals who have not been screened by echo or genetic testing (unpublished data).