[Mutation analysis of SMN gene in a patient and his family with spinal muscular atrophy].
OBJECTIVE
To perform mutation analysis and describe the genotype of the SMN gene in a patient with spinal muscular atrophy (SMA) and his family.


METHODS
Deletion analysis of the SMN1 exon 7 by conventional PCR-restriction fragment length polymorphism (RFLP) and allele-specific PCR, and gene dosage of SMN1 and SMN2 by multiplex ligation-dependent probe amplification (MLPA) were performed for the patient and his parents; reverse transcriptase (RT)-PCR and sequencing were performed for the patient. To determine whether the SMN variant was exclusive to transcripts derived from SMN1, the RT-PCR product of the patient was subcloned and multiple clones were sequenced directly; PCR of SMN exon 5 from the genomic DNA of the parents and direct sequencing were performed to confirm the mutation.


RESULTS
In SMN1 exon 7 deletion analysis, no homozygous deletion of the SMN1 was observed in the family; the gene dosage analysis by MLPA showed that the patient had 1 copy of SMN1 and 1 copy of SMN2 his father had 2 copies of SMN1 and 2 copies of SMN2, and his mother had 1 copy of SMN1 and no SMN2. A previously unreported missense mutation of S230L was identified from the patient and this mutation was also found in his father.


CONCLUSIONS
A novel missense mutation of S230L was identified in the SMA family and the genotype of the family members were investigated.
Fuzhou General Hospital, Nanjing Military Region, Fuzhou, Fujian, 350025 People's Republic of China.
Jian
J
Zeng
Yan-hong
YH
Lin
Ai-zhen
AZ
Yan
Mei-ying
MY
Cai
Long-feng
LF
Ke
Feng-hua
FH
Lan
D001483:Base Sequence; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005091:Exons / Q000235:genetics; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009134:Muscular Atrophy, Spinal / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055532:SMN Complex Proteins / Q000235:genetics*; D014897:Spinal Muscular Atrophies of Childhood / Q000235:genetics; D055533:Survival of Motor Neuron 1 Protein / Q000235:genetics*; D055517:snRNP Core Proteins / Q000235:genetics
D055532:SMN Complex Proteins; D055533:Survival of Motor Neuron 1 Protein; D055517:snRNP Core Proteins