1. ¹Genetics Clinic Unit, Instituto da Criança do Hospital das Clínicas, University of São Paulo, Sao Paulo, Brazil
2. ²Robarts Research Institute, 406-100 Perth Drive, London, ON, Canada, N6A 5K8
3. ³Department of Neurology, University of Sao Paulo, Sao Paulo, Brazil
4. ⁴ Av. Dr. Enéas Carvalho de Aguiar, 647, Sao Paulo 05403-900, Brazil

Correspondence: Debora R Bertola, Av. Dr. Enéas Carvalho de Aguiar, 647, Sao Paulo 05403-900, Brazil. E-mail: deborarb@icr.hcnet.usp.br

Received 3 April 2006; Accepted 7 May 2006; Published online 25 July 2006.

Abstract

Cockayne syndrome is a rare autosomal recessive neurodegenerative disorder. It is considered to be a heterogeneous condition based on complementation in cell fusion studies, with two major forms, namely CS-A and CS-B. CKN1 is the gene responsible for CS-A, whose mutations disrupt the transcription-coupled repair system of the actively transcribed DNA. Mutation analysis of the CKN1 gene in eight typical CS-A Brazilian patients from six families showed a gene alteration in all of them. We found a total of five novel mutations that were absent from healthy control subjects. Six affected subjects were simple homozygotes and two affected siblings were each compound heterozygotes. While the findings extend the range of mutations in CS-A, there is no obvious genotype-phenotype correlation across the mutational spectrum.