Introduction: Cockayne syndrome (CS) is a rare autosomal-recessive disorder secondary to a DNA repair abnormality. It is characterized by clinical and genetic heterogeneity.

Objective: To determine the clinical and genetic characteristics of a Maghrebian series with CS.

Patients and methods: Retrospective study conducted over 13 years (2005 to 2017) including 13 patients (10 Tunisian families, 1 Libyan family) followed for a CS. Clinical, paraclinical and genetic data were collected and analyzed.

Results: 9 boys and 4 girls with an average age of 2.8 years. Consanguinity was noted in 8 families. The first symptom was psychomotor delay. Microcephaly, spastic paraparesis, facial dysmorphism, mental retardation, language delay and deafness were objectified in all cases. Photosensitivity was noted in 8 cases. Ophthalmologic examination showed cataract in 3 cases and pigmentary retinopathy in one case. Lenticular calcifications (10/12), cerebellar atrophy (6/12) and hypomyelinating leukodystrophy (8/12) were found. Demyelinating peripheral neuropathy was objectified in 2 patients. The CS was genetically confirmed in 7 families (founder mutation of the ERCC8 gene in 5 families with the classical phenotype of the disease, a new mutation of ERCC8 gene associated with a severe phenotype without photosensitivity in one family and a novel mutation in ERCC6 gene in one family).

Conclusion: Our study illustrates the clinical heterogeneity of the CS and highlights mainly a recurrent founder mutation specific to the North African population with a genotype phenotype correlation. Targeted mutational research in the CS will enable early diagnosis and facilitate genetic counseling in the Maghreb countries.