This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Rozenberg, R. Articles by Pereira, L.V. Search for Related Content PubMed PubMed Citation Articles by Rozenberg, R. Articles by Pereira, L.V. Social Bookmarking                         What's this?

Diagnosis and Molecular Characterization of Nonclassic Forms of Tay-Sachs Disease in Brazil

Human Genome Research Center, Department of Biology Biosciences Institute, University of São Paulo São Paulo, Brazil

F. Kok, MD, PhD

Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil

M.G. Burin, MS

Medical Genetic Service, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, UFRGS Porto Alegre, RS, Brazil

M.C. Sá Miranda, PhD

Instituto de Biologia Molecular e Celular, University of Porto Porto, Portugal

C. Vasques, MD

Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil

A.M.M. Henriques-Souza, MD

Instituto Materno Infantil de Pernambuco, Ceará, Brazil

R. Giugliani, PhD

Medical Genetic Service, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, UFRGS, Porto Alegre, RS, Brazil

Mariz Vainzof, PhD

Human Genome Research Center, Department of Biology, IB-University of São Paulo, São Paulo, Brazil, mvainzof{at}usp.br

L.V. Pereira, PhD

Human Genome Research Center, Department of Biology, IB-University of São Paulo, São Paulo, Brazil

Molecular analysis of five Brazilian families, including eight patients presenting with nonclassic Tay-Sachs disease, was performed to identify frequent causative mutations and their correlation with clinical course. Three patients were affected by the B1 subacute variant and were shown to carry the R178H mutation (the DN allele), which is also common among Portuguese patients. Two of them were compound heterozygotes, whereas the third presented with the mutation in both alleles. Since Brazil was a Portuguese colony for over two centuries, common ancestry might be the probable explanation. The fourth patient presented with a juvenile phenotype and carries the R499H mutation, which has been reported only once worldwide and is associated with residual enzyme activity, responsible for a slower clinical course. The fifth family, of an Ashkenazi Jewish background, showed an extensive intrafamilial clinical variability among three affected sibs presenting with muscle atrophy, ataxia, and psychiatric symptoms. They were first diagnosed as having atypical spinal muscular atrophy and, subsequently, spinocerebellar ataxia, but, recently, the diagnosis of late-onset Tay-Sachs disease was confirmed based on reduced plasma hexosaminidase A activity and the G269S/InsTATC1278 genotype. It is therefore highly recommended to test patients with a similar clinical history for Tay-Sachs disease. In the same family, one first cousin committed suicide at the age of 24 years, presenting with a clinical phenotype that suggested an undiagnosed case and highlighting the effect of the intrafamilial clinical variability in delaying a prompt diagnosis. It is now recognized that his parents are, in fact, a carrier couple. Additionally, another relative had been previously identified as a heterozygote in a Tay-Sachs disease screening program, but the information was not shared among the family. Since this information might anticipate diagnosis and genetic counseling, it is advisable that heterozygote screening programs encourage families to share genetic information. (J Child Neurol 2006;21:540—544; DOI 10.2310/7010.2006.00102).

Journal of Child Neurology, Vol. 21, No. 6, 540-544 (2006)
DOI: 10.1177/08830738060210061101


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?