Mosaicism of alpha-synuclein gene rearrangements: Report of two unrelated cases of early-onset parkinsonism

CLAUDIA PERANDONES; GIUGNI JC; CALVO DS; GABRIELA BEATRIZ RAINA; V. VOLPINI; DE JORGE LOPEZ L.; CORACH D; CAPUTO M; RADRIZZANI MARTIN; FEDERICO EDUARDO MICHELI

PARKINSONISM & RELATED DISORDERS

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2014 vol. 20 p. 558 - 561

1353-8020

In genetics, the term ?mosaicism? describes the situation in which groups of cells have a different genetic composition to other cells in an organism. Somatic gene rearrangements due to multiplication or deletion of genes (copy number variation) and/or sections of chromosomes can lead to mosaicism. The presence of multiple copies of the alpha-synuclein gene (SNCA) is known to be associated with Parkinson´s disease (PD) and the severity of symptoms increases with the number of copies of the gene [1]. While the features of PD associated with duplication of SNCA are usually (but not always) typical of the condition [2] and [3], patients with triplicate copies have atypical features, including rapidly evolving symptoms, severe cognitive impairment, limited response to levodopa, more severe symptoms of dementia and more frequent urinary incontinence [2]. A lack of studies of mosaicism in PD illustrates that the prevalence and mechanism of these rearrangements have not yet been elucidated.