Survival motor neuron (SMN) gene: a gene for spinal muscular atrophy

Abstract

The present invention relates to the discovery of the human survival motor-neuron gene or SMD gene, which is a chromosome 5-SMA (Spinal Muscular Atrophy) determining gene. The present invention further relates to the nucleotide sequence encoding the SMN gene and corresponding amino acid sequence, a vector containing the gene encoding the SMN protein or a DNA sequence corresponding to the gene and transformant strains containing the SMN gene or a DNA sequence corresponding to the gene.

1 . A method of detecting the presence or absence of a Survival Motor Neuron (SMN) gene in a biological sample, the method comprising: 
 a) contacting the sample with a oligonucleotide probe that hybridizes to all or a portion of the SMN gene, wherein the gene comprises SEQ ID NO: 22; and    b) analyzing the sample to detect the presence or absence of hybridized probe, wherein the presence of hybridized probe indicates the presence of the SMN gene in the sample, and the absence of hybridized probe indicates the absence of the SMN gene in the sample.    
     
     
         2 . A method of detecting the presence or absence of a Survival Motor Neuron (SMN) gene in a nucleic acid sample, the method comprising: 
 a) amplifying nucleic acid contained in the sample with primers that amplify all or a portion of the SMN gene, wherein the gene comprises SEQ ID NO: 22; and    b) detecting the presence or absence of amplified product, wherein the presence of amplified product indicates the presence of the SMN gene in the sample and the absence of amplifies product indicates the absence of the SMN gene in the sample.    
     
     
         3 . The method of  claim 2 , wherein the primers comprise a sequence selected from the group consisting of SEQ ID NOS: 5 to 8 and 24 to 57.  
     
     
         4 . A method for detecting the presence or absence of a truncation, a deletion or a mutation in a Survival Motor Neuron (SMN) gene comprising SEQ ID NO: 22, in a patient sample, comprising: 
 a) amplifying DNA obtained from a patient sample with primers, wherein each primer comprises a sequence selected from the group consisting of SEQ ID NOS: 5 to 8 and 24 to 57;    b) subjecting the amplified DNA to Single-Strand Conformation Polymorphism (SSCP) analysis, wherein the analysis comprises comparing a pattern of DNA fragments obtained from the patient sample to a pattern of DNA fragments obtained from a control sample to detect alterations in the patient gene; and    c) detecting the presence or absence of the truncation, deletion or mutation in the Survival Motor Neuron gene.    
     
     
         5 . The method of  claim 4 . wherein the detection of a truncation, deletion or mutation in the Survival Motor Neuron gene is indicative of a Spinal Muscular Atrophy.  
     
     
         6 . The method of  claim 4 , wherein step (a) is replaced with a step of digesting DNA obtained from a patient sample with a Bsrl enzyme.  
     
     
         7 . A method for detecting the presence or absence of Spinal Muscular Atrophy in an individual, comprising: 
 a) hybridizing a DNA sample obtained from the individual with a DNA probe comprising all or part of the DNA sequence of SEQ ID NO: 22 under conditions having the stringency of 10% Dextran Sulphate Sodium, 1 M NaCl, 0.05M Tris-HCl pH 7.5, 0.005M EDTA and 1% SDS at 65° C.; and    b) detecting the hybrids formed, wherein the absence of detectable hybrids is indicative of the presence of Spinal Muscular Atrophy in the individual.    
     
     
         8 . The method according to  claim 3 , wherein the probe is detectably labeled.  
     
     
         9 . A method for detecting the presence or absence of one or more mutations in a Survival Motor Neuron (SMN) gene in a nucleic acid sample, comprising: 
 a) analyzing the nucleotide sequence of the nucleic acid in the sample, and    b)comparing the nucleotide sequence of the sample nucleic acid to reference SMN nucleic acid sequence, wherein the reference SMN nucleic acid sequence consists of SEQ ID NO: 22, and    c) determining the presence or absence of differences between the sequence of the nucleic acid in the sample and the sequence of the reference SMN nucleic acid, wherein the presence of one or more differences in the nucleic acid sequence of the sample indicates the presence of one or more mutations in the sample SMN gene, and the absence of one or more differences in the nucleic acid sample indicates the absence of mutations in the sample SMN gene.    
     
     
         10 . The method of  claim 9 , wherein the detection of a truncation, deletion or mutation in the Survival Motor Neuron gene is indicative of a Spinal Muscular Atrophy.  
     
     
         11 . A kit comprising: 
 a) an oligonucleotide probe that hybridizes to all or portion of an SMN gene wherein the gene comprises SEQ ID NO: 22; and    b) reagents for a hybridization reaction.    
     
     
         12 . The kit according to  claim 11 , wherein said oligonucleotide probe is labelled.  
     
     
         13 . The kit according to  claim 12 , wherein said label is an enzyme label or a radioactive label.  
     
     
         14 . A kit for the in vitro detection of a truncation, a deletion or a mutation of a survival motor neuron gene comprising SEQ ID NO: 22 comprising: 
 a) a set of primers wherein said primers comprise a sequence selected from the group consisting of SEQ ID NOS: 5 to 8 and 24 to 57;    b) reagents for an amplification reaction; and    c) an oligonucleotide probe for the detection of the amplified product.    
     
     
         15 . The kit according to  claim 14 , wherein said oligonucleotide probe is labelled.  
     
     
         16 . The kit according to  claim 15 , wherein said label is an enzyme label or a radioactive label.  
     
     
         17 . A kit for the in vitro detection of a truncation, a deletion or a mutation of a survival motor neuron gene comprising: 
 d) a set of primers wherein said primers comprise a sequence selected from the group consisting of SEQ ID NOS: 5 to 8 and 24 to 57, wherein the primers amplify a survival motor neuron gene comprising SEQ ID NO: 22;    e) reagents for an amplification reaction; and    f) an oligonucleotide probe for the detection of the amplified product.    
     
     
         18 . The kit according to  claim 17 , wherein said oligonucleotide probe is labelled.  
     
     
         19 . The kit according to  claim 18 , wherein said label is an enzyme label or a radioactive label.