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Title: Association between AgI-CA alleles and severity of autosomal recessive proximal spina lmuscular atrophy

Journal Article · · American Journal of Human Genetics
OSTI ID:56734
; ; ; ; ;  [1];  [2]; ;  [3];  [4]
  1. Ohio State Univ., Columbus, OH (United States)
  2. McGill Univ. (Canada)
  3. Hopital Sainte-Justine, Montreal (Canada)
  4. Univ. of California, Irvine, CA (United States); and others

The gene for autosomal recessive proximal spinal muscular atrophy (SMA) has been mapped to an 850-kb interval on 5q11.2-q13.3, between the centromeric D5S823 and telomeric D5S557 markers. We report a new complex marker, Ag1-CA, that lies in this interval, whose primers produce one, two, or rarely three amplification-fragment-length variants (AFLVs) per allele. Class I chromosomes are those which amplify a single AFLV allele, and class II chromosomes are those which amplify an allele with two or three AFLVs. Ag1-CA shows highly significant allelic association with type I SMA in both the French Canadian (Hopital Sainte-Justine (HSJ)) and American (Ohio State University (OSU)) populations (P < .0001). Significant association between the Ag1-CA genotype and disease severity was also observed. Type I patients were predominantly homozygous for class I chromosomes (P = .0003 OSU; P = 0.0012 HSJ), whereas the majority of type II patients were heterozygous for class I and II chromosomes (P = .0014 OSU; P = .001 HSJ). There was no significant difference in Ag1-CA genotype frequencies between type III patients (P = .5 OSU; P = .25 HSJ) and the paired normal chromosomes from both carrier parents. Our results indicate that Ag1-CA is the most closely linked marker to SMA and defines the critical candidate-gene region. Finally, we have proposed a model that should be taken into consideration when screening candidates SMA genes.

OSTI ID:
56734
Journal Information:
American Journal of Human Genetics, Vol. 55, Issue 6; Other Information: PBD: Dec 1994
Country of Publication:
United States
Language:
English