Identification of novel SMN1 subtle mutations using an allelic-specific RT-PCR
| Autor: | Xiao-Min Ying, Xiao-Xing Qu, Jingmin Zhang, Bing Xiao, Wen-ting Jiang, Xing Ji, Yingwei Chen, Meng-Yao Dai, Xiaoqing Liu, Yan Xu, Yu Liu |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Male
0301 basic medicine China DNA Mutational Analysis SMN1 Biology medicine.disease_cause Muscular Atrophy Spinal 03 medical and health sciences 0302 clinical medicine medicine Humans Point Mutation Multiplex ligation-dependent probe amplification Allele Indel Gene Genetics (clinical) Genetics Mutation Reverse Transcriptase Polymerase Chain Reaction Point mutation Infant SMA Survival of Motor Neuron 1 Protein Pedigree nervous system diseases Survival of Motor Neuron 2 Protein 030104 developmental biology Neurology Pediatrics Perinatology and Child Health Female Neurology (clinical) 030217 neurology & neurosurgery |
| Zdroj: | Neuromuscular Disorders. 30:219-226 |
| ISSN: | 0960-8966 |
| DOI: | 10.1016/j.nmd.2019.11.010 |
| Popis: | Spinal muscular atrophy (SMA) is caused by homozygous deletions of the SMN1 gene in approximately 95% of patients. The remaining 5% of patients with SMA retain at least one copy of the SMN1 gene carrying insertions, deletions, or point mutations. Although molecular genetic testing for most SMA patients is quite easy, diagnosing "nondeletion" SMA patients is still compromised by the presence of a highly homologous SMN2 gene. In this study, we analyzed the SMN1/SMN2 copy number by quantitative PCR and multiplex ligation-dependent probe amplification (MLPA). Further, common primers for both SMN1 and SMN2 sequences were used to screen DNA intragenic mutations. To confirm whether the identified mutations occurred in SMN1 or SMN2, we improved the traditional RT-PCR method by only amplifying SMN1 transcripts using an allelic-specific PCR (AS-RT-PCR) strategy. We identified six SMN1 point mutations and small indels in 8 families, which included c.683T>A, c.22dupA, c.815A>G, c.19delG, c.551_552insA and c.401_402delAG. To the best of our knowledge, the latter three have never been previously reported. The most common mutation in Chinese patients is c.22dupA, which was identified in three families. In this work, we demonstrated AS-RT-PCR to be reliable for identifying SMN1 subtle mutations, especially the prevalent mutation c.22dupA in Chinese SMA patients. By reviewing published papers and summarizing reported SMN1 mutations, a distinct ethnic specificity was found in SMA patients from China. Our research extends the SMN1 mutation spectrum. |
| Databáze: | OpenAIRE |
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