title: Carrier incidence for spinal muscular atrophy in southern Chinese.
abstract: A real time quantitative PCR (QPCR) method using TaqMan technology was used to assess the copy number of the two survival motor neuron genes (SMN1 and SMN2) on chromosome 5q13. This allows the accurate determination of carriers for spinal muscular atrophy (SMA), with one copy of SMN1. Analysis of 569 normal southern Chinese individuals revealed a carrier incidence of 1.6%, similar to that found in the western society. Study of 42 obligatory carriers showed a (2 + 0) genotype in two (4.8 %). In 27 SMA patients with homozygous deletion of the SMN1 gene, the number of SMN2 gene correlated with disease phenotype, with 68% of type II and III patients carrying three or more SMN2 genes, whilst the incidence of three or more SMN2 genes in the normal population was 1.57%.
authors.affiliation: University Department of Medicine, Queen Mary Hospital, Pokfulam Road, Hong Kong. vnychana@hkucc.hku.hk
authors.forename: Vivian
authors.initials: V
authors.lastname: Chan
authors.forename: Ben
authors.initials: B
authors.lastname: Yip
authors.forename: Irene
authors.initials: I
authors.lastname: Yam
authors.forename: Patrick
authors.initials: P
authors.lastname: Au
authors.forename: Che-Kit
authors.initials: CK
authors.lastname: Lin
authors.forename: Virginia
authors.initials: V
authors.lastname: Wong
authors.forename: Tai-Kwong
authors.initials: TK
authors.lastname: Chan
mesh_terms: D044466:Asian People / Q000235:genetics* / Q000706:statistics & numerical data; D002681:China / Q000453:epidemiology; D017362:Cyclic AMP Response Element-Binding Protein; D006580:Genetic Carrier Screening; D006801:Humans; D015994:Incidence; D009134:Muscular Atrophy, Spinal / Q000453:epidemiology* / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics; D016601:RNA-Binding Proteins; D055532:SMN Complex Proteins; D055533:Survival of Motor Neuron 1 Protein; D055540:Survival of Motor Neuron 2 Protein
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; D055532:SMN Complex Proteins; C526471:SMN1 protein, human; C526477:SMN2 protein, human; D055533:Survival of Motor Neuron 1 Protein; D055540:Survival of Motor Neuron 2 Protein