A novel cDNA detects homozygous microdeletions in greater than 50% of type I spinal muscular atrophy patients.
Spinal muscular atrophy (SMA) is the second most common lethal, autosomal recessive disease in Caucasians (after cystic fibrosis). Childhood SMAs are divided into three groups (type I, II and III), which are allelic variants of the same locus in a region of approximately 850 kb in chromosome 5q12-q13, containing multiple copies of a novel, chromosome 5-specific repeat as well as many atypical pseudogenes. This has hampered the identification of candidate genes. We have identified several coding sequences unique to the SMA region. A genomic fragment detected by one cDNA is homozygously deleted in 17/29 (58%) of type I SMA patients. Of 235 unaffected individuals examined, only two showed the deletion and both are carriers of SMA. Our results suggest that deletion of at least part of this novel gene is directly related to the phenotype of SMA.
Thompson
T G
TG
Department of Biological Chemistry, College of Medicine, University of California, Irvine 92717.
DiDonato
C J
CJ
Simard
L R
LR
Ingraham
S E
SE
Burghes
A H
AH
Crawford
T O
TO
Rochette
C
C
Mendell
J R
JR
Wasmuth
J J
JJ
D001483:Base Sequence; D002874:Chromosome Mapping; D002895:Chromosomes, Human, Pair 5; D018076:DNA, Complementary / Q000235:genetics*; D005091:Exons; D006720:Homozygote; D006801:Humans; D008969:Molecular Sequence Data; D009134:Muscular Atrophy, Spinal / Q000145:classification / Q000235:genetics*; D010641:Phenotype; D012091:Repetitive Sequences, Nucleic Acid; D017384:Sequence Deletion; D014158:Transcription, Genetic
D018076:DNA, Complementary