The new mutation, E46K, of α‐synuclein causes parkinson and Lewy body dementia

JJ Zarranz, J Alegre… - Annals of Neurology …, 2004 - Wiley Online Library
JJ Zarranz, J Alegre, JC Gómez‐Esteban, E Lezcano, R Ros, I Ampuero, L Vidal, J Hoenicka
Annals of Neurology: Official Journal of the American Neurological …, 2004Wiley Online Library
Familial parkinsonism and dementia with cortical and subcortical Lewy bodies is
uncommon, and no genetic defect has been reported in the previously described sibships.
We present a Spanish family with autosomal dominant parkinsonism, dementia, and visual
hallucinations of variable severity. The postmortem examination showed atrophy of the
substantia nigra, lack of Alzheimer pathology, and numerous Lewy bodies which were
immunoreactive to α‐synuclein and ubiquitin in cortical and subcortical areas. Sequencing …
Abstract
Familial parkinsonism and dementia with cortical and subcortical Lewy bodies is uncommon, and no genetic defect has been reported in the previously described sibships. We present a Spanish family with autosomal dominant parkinsonism, dementia, and visual hallucinations of variable severity. The postmortem examination showed atrophy of the substantia nigra, lack of Alzheimer pathology, and numerous Lewy bodies which were immunoreactive to α‐synuclein and ubiquitin in cortical and subcortical areas. Sequencing of the α‐synuclein gene showed a novel, nonconservative E46K mutation in heterozygosis. The E46K mutation was present in all affected family members and in three young asymptomatic subjects, but it was absent in healthy and pathological controls. The novel mutation, that substitutes a dicarboxylic amino acid, glutamic acid, with a basic amino acid such as lysine in a much conserved area of the protein, is likely to produce severe disturbance of protein function. Our data show that, in addition to the previously described hereditary α‐synucleinopathies, dementia with Lewy bodies is related to mutation of α‐synuclein.
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