Case report: A novel mutation in RTEL1 gene in dyskeratosis congenita

Dyskeratosis congenita (DKC), also known as Zinsser-Cole-Engman syndrome, is a telomeropathy typically presenting as a triad of leukoplakia, nail dystrophy, and reticular hyperpigmentation. Reported genetic mutations linked to DKC include , , , , , , , , and . Homozygous, compound heterozygous, and heterozygous mutations in ( , regulator of telomere elongation helicase 1) gene on chromosome 20q13 are known to cause autosomal dominant as well as recessive DKC. Pathogenic variants of gene in patients include c.2288G>T (p. Gly763Val), c.3791G>A (p. Arg1264His), and p. Arg981Trp. We report a novel homozygous variant of , transcript ID: ENST00000360203.11, exon 24, c.2060C>T (p.Ala687Val), in a patient of DKC presenting with leukoplakia, dystrophic nails, reticulate pigmentation, and positive family history of a similar phenotype. The novel variant, reported as a variant of uncertain significance, may therefore be considered diagnostic for DKC in a Pakistani population.