First molecular study in Lebanese patients with Cockayne syndrome and report of a novel mutation in ERCC8 gene

BACKGROUND: Cockayne Syndrome (CS) is a rare autosomal recessive disorder characterized by neurological and sensorial impairment, dwarfism, microcephaly and photosensitivity. CS is caused by mutations in ERCC6 (CSB) or ERCC8 (CSA) genes. METHODS: Three patients with CS were referred to the Medical Genetics Unit of Saint Joseph University. Sanger sequencing of both ERCC8 and ERCC6 genes was performed: ERCC8 was tested in all patients while ERCC6 in one of them. RESULTS: Sequencing led to the identification of three homozygous mutations, two in ERCC8 (p.Y322* and c.843 + 1G > C) and one in ERCC6 (p.R670W). All mutations were previously reported as pathogenic except for the c.843 + 1G > C splice site mutation in ERCC8 which is novel. CONCLUSIONS: Molecular diagnosis was established in all patients included in our study. A genotype-phenotype correlation is discussed and a link, between mutations and some specific religious communities in Lebanon, is suggested. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12881-018-0677-7) contains supplementary material, which is available to authorized users.