A.The family history reconstruction. The arrow denotes the proband. Symbols (+) and (-) indicate LAMP2 mutation carriers and non-carriers, respectively. The absence of symbol denotes that no DNA was available for analysis. 2001, 2006, 2013 – years of birth; B. X-chromosome inactivation pattern in the proband (II-2; extracted from heart muscle) and affected son (III-2; extracted from buccal epithelium). Undigested (–Hin6I) and digested (+Hin6I) DNA samples are shown in the upper and lower plots respectively. The only 288-bp PCR fragment detected in the son (III-2) indicating the chromosome bearing c.190_191delАС. The absence of the corresponding peak area after Hin6I denoted that digestion of the active allele was sufficient; C. Mutation detection by DNA sequencing; D. Relationship between age of cardiomyopathy onset and inactivation level of a healthy allele in Danon patients. The single circles represent the data points, the line represents the quadratic trendline of the corresponding data set, and the numbers correspond to the cases in Table 1.