title: Genomic rearrangements in childhood spinal muscular atrophy: linkage disequilibrium with a null allele.
abstract: Autosomal recessive childhood onset spinal muscular atrophy has been mapped to chromosome 5q13. We report the analysis of a polymorphic microsatellite which shows linkage disequilibrium with the disease. The linkage disequilibrium is observed with a null allele which is seen as the non-inheritance of alleles from one or both parents. The inheritance of a null allele was observed in 26 out of 36 (72%) informative childhood onset spinal muscular atrophy (SMA) families tested, of all types of severity and from a variety of ethnic backgrounds. In seven families segregating for the severe Werdnig-Hoffmann or SMA type I, no alleles were inherited from either parent using this microsatellite. This null allele may represent a deletion which is either closely associated with, or causes, the disease.
authors.affiliation: Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford, UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: Daniels
authors.forename: L
authors.initials: L
authors.lastname: Campbell
authors.forename: N R
authors.initials: NR
authors.lastname: Rodrigues
authors.forename: M J
authors.initials: MJ
authors.lastname: Francis
authors.forename: K E
authors.initials: KE
authors.lastname: Morrison
authors.forename: M
authors.initials: M
authors.lastname: McLean
authors.forename: A
authors.initials: A
authors.lastname: MacKenzie
authors.forename: J
authors.initials: J
authors.lastname: Ignatius
authors.forename: V
authors.initials: V
authors.lastname: Dubowitz
authors.forename: K E
authors.initials: KE
authors.lastname: Davies
mesh_terms: D000483:Alleles; D002648:Child; D002895:Chromosomes, Human, Pair 5 / Q000235:genetics*; D015342:DNA Probes; D004276:DNA, Satellite / Q000235:genetics; D005260:Female; D005387:Finland; D017353:Gene Deletion; D015321:Gene Rearrangement / Q000235:genetics*; D005808:Genes, Recessive / Q000235:genetics; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics*; D008297:Male; D009134:Muscular Atrophy, Spinal / Q000235:genetics*; D010375:Pedigree; D011110:Polymorphism, Genetic
chemical_list: D015342:DNA Probes; D004276:DNA, Satellite