Genomic rearrangements in childhood spinal muscular atrophy: linkage disequilibrium with a null allele.
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.
Daniels
R J
RJ
Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford, UK.
Campbell
L
L
Rodrigues
N R
NR
Francis
M J
MJ
Morrison
K E
KE
McLean
M
M
MacKenzie
A
A
Ignatius
J
J
Dubowitz
V
V
Davies
K E
KE
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
D015342:DNA Probes; D004276:DNA, Satellite