Quantitative analysis of SMN1 gene and estimation of SMN1 deletion carrier frequency in Korean population based on real-time PCR.
Spinal muscular atrophy (SMA) is an autosomal recessive disorder, caused by homozygous absence of the survival motor neuron gene (SMN1) in approximately 94% of patients. Since most carriers have only one SMN1 gene copy, several SMN1 quantitative analyses have been used for the SMA carrier detection. We developed a reliable quantitative real-time PCR with SYBR Green I dye and studied 13 patients with SMA and their 24 parents, as well as 326 healthy normal individuals. The copy number of the SMN1 gene was determined by the comparative threshold cycle (Ct) method and albumin was used as a reference gene. The homozygous SMN1 deletion ratio of patients was 0.00 and the hemizygous SMN1 deletion ratio of parents ranged from 0.39 to 0.59. The deltadelta Ct ratios of 7 persons among 326 normal individuals were within the carrier range, 0.41-0.57. According to these data, we estimated the carrier and disease prevalence of SMA at 1/47 and 1/8,496 in Korean population, respectively. These data indicated that there would be no much difference in disease prevalence of SMA compared with western countries. Since the prevalence of SMA is higher than other autosomal recessive disorders, the carrier detection method using real-time PCR could be a useful tool for genetic counseling.
Lee
Tae-Mi
TM
Division of Genetic Disease, Department of Biomedical Sciences, National Institute of Health, Seoul, Korea.
Kim
Sang-Wun
SW
Lee
Kwang-Soo
KS
Jin
Hyun-Seok
HS
Koo
Soo Kyung
SK
Jo
Inho
I
Kang
Seongman
S
Jung
Sung-Chul
SC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017362:Cyclic AMP Response Element-Binding Protein; D004252:DNA Mutational Analysis / Q000379:methods*; D005260:Female; D006580:Genetic Carrier Screening / Q000379:methods; D020022:Genetic Predisposition to Disease / Q000453:epidemiology; D005820:Genetic Testing / Q000379:methods*; D006579:Heterozygote; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009134:Muscular Atrophy, Spinal / Q000453:epidemiology* / Q000235:genetics / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000235:genetics*; D011110:Polymorphism, Genetic; D019655:Quantitative Trait, Heritable; D016601:RNA-Binding Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D055532:SMN Complex Proteins; D055533:Survival of Motor Neuron 1 Protein
D017362:Cyclic AMP Response Element-Binding Protein; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; D055532:SMN Complex Proteins; C526471:SMN1 protein, human; D055533:Survival of Motor Neuron 1 Protein