Cockayne syndrome in an Iranian pedigree with a homozygous missense variant in the ERCC6 gene

Cockayne syndrome (CS), a rare autosomal recessive multisystem disorder, is characterized by mental retardation, progressive growth failure, neurodegeneration, microcephaly, retinal degeneration, sensorineural deafness, cutaneous photosensitivity and premature aging. This genetic disorder is a member of the nucleotide excision repair (NER) disorder family. Excision repair cross-complementing, group 6 (ERCC6) and excision repair cross-complementing, group 8 (ERCC8) gene mutations underlie most CS cases. Furthermore, a small number of CS cases are caused by mutations in other NER genes. Furthermore, a small number of Cockayne syndrome cases are caused by certain mutations in the XP genes. This article describes the symptoms of Cockayne syndrome in an 8-year-old Iranian child. Using whole exome sequencing, we discovered a homozygous missense mutation in the ERCC6 gene, c.2551 T > A; p Trp851Arg.