Pedigrees of 6 families identified with RTEL1 variants. Pedigrees from proband KCH-11, KCH-9, KCH-8, NIH-1, NIH-2, and NIH-5, respectively. The RTEL1 variant presented in the family is described above each pedigree. Arrows indicate the probands of each family. Open circles and squares show females and males who are noncarriers, respectively. Half-filled or solid circles and squares represent individuals who are heterozygous or homozygous for the RTEL1 variant, respectively. A line through the circle or square indicates individuals who are deceased. When tested, TL and clinical features are described in the figure under each individual. Relatives who lack clinical and mutational data are indicated by a question mark. For families NIH-1 and NIH-2, probands were identified as compound heterozygous (half-red, half–light red, square). In NIH-1, the proband’s father and mother carried the D719N (half-red square) and the P871L (half–light red circle) variants, respectively, both heterozygous. In NIH-2, the father was not screened, but the mother carried the G951S variant in heterozygosity. BMF, bone marrow failure; CY/HD, compound heterozygous for C282Y and H63D hereditary hemochromatosis genes; KCH, King’s College Hospital cohort; NIH, National Institutes of Health cohort; MAA, moderate aplastic anemia; TLCO, transfer factor of the lung for carbon monoxide.