title: Genetic and clinical analysis in a Chinese parkinsonism-predominant spinocerebellar ataxia type 2 family.
abstract: Parkinson's disease is a degenerative central nervous system disorder that often impairs motor skills, speech and other functions. We discovered a large Chinese family showing primarily parkinsonism symptoms with autosomal dominant inheritance. Six affected individuals in the family showed typical parkinsonism symptoms, including pill-rolling tremor. Two other affected individuals showed cerebellar ataxia symptoms. A whole-genome scan using the 50K single nucleotide polymorphism array with three different linkage methods detected two positive regions on chromosome 12q24.1 and 5q13.3. The ATXN2 gene, responsible for spinocerebellar ataxia type 2 (SCA2) was located precisely in the center of the positive region on chromosome 12. Further analysis of SCA2 revealed heterozygous pathological CAG expansions in the family. The affected individuals' symptoms were typical of parkinsonism, but complex. Inverse correlation between CAG repeat size and age of onset is not obvious in this pedigree. This parkinsonism-predominant SCA2 family shared the same disease gene locus with other 'standard' SCA2 families, but it is possible that variations in one or more modifier genes might account for the parkinsonism-predominant SCA2 predisposition observed in this pedigree.
authors.affiliation: The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.forename: Wataru
authors.initials: W
authors.lastname: Satake
authors.forename: Changjun
authors.initials: C
authors.lastname: Zhang
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Nagai
authors.forename: Youyong
authors.initials: Y
authors.lastname: Tian
authors.forename: Shouzhi
authors.initials: S
authors.lastname: Fu
authors.forename: Jiankun
authors.initials: J
authors.lastname: Yu
authors.forename: Yaping
authors.initials: Y
authors.lastname: Qian
authors.forename: Yuan
authors.initials: Y
authors.lastname: Qian
authors.forename: Jiayou
authors.initials: J
authors.lastname: Chu
authors.forename: Tatsushi
authors.initials: T
authors.lastname: Toda
mesh_terms: D044466:Asian People / Q000235:genetics; D000067528:Ataxins; D002531:Cerebellum / Q000473:pathology; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D002895:Chromosomes, Human, Pair 5 / Q000235:genetics*; D042622:DNA Repeat Expansion / Q000235:genetics; D005799:Genes, Dominant / Q000235:genetics; D008040:Genetic Linkage; D006801:Humans; D008279:Magnetic Resonance Imaging; D009419:Nerve Tissue Proteins / Q000235:genetics; D010300:Parkinson Disease / Q000235:genetics* / Q000473:pathology*; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D020754:Spinocerebellar Ataxias / Q000235:genetics* / Q000473:pathology*
chemical_list: D000067528:Ataxins; D009419:Nerve Tissue Proteins