TERC and Hermansky-Pudlak syndrome: Eleven of 12 patients with HPS had homozygous mutations (c.1472_1487dup16) in HPS1 (Table 2); one patient with HPS had a compound heterozygous mutation in HPS1. All patients with FPF had telomere disease; four patients had single mutations in TERT, and one had a variant in TERC.