The inheritance of novel homozygous TERT mutations. The index case of each consanguineous family is highlighted by an arrow. Inheritance of a single mutated TERT allele in male and female members is indicated by half black squares or circles. Presence of a wild-type TERT allele in male and female members is indicated by half white squares or circles. Therefore the parents in both families are heterozygous for their respective TERT mutation, while the 2 affected female patients, are homozygous mutant for their respective TERT mutation (a solid black circle), suggesting that both the R811C and R901W TERT mutations segregate in these 2 families in an autosomal recessive manner. Solid gray circles or squares indicate that these samples were not available for screening. Specific clinical symptoms of interest are highlighted underneath the age of each individual.