Investigation and analysis of genetic testing in a SMA cohort based on the national rare diseases registry system of China
10.3760/cma.j.cn114452-20200918-00735
- VernacularTitle:基于脊髓性肌萎缩症注册队列人群的基因诊断技术应用调查分析
- Author:
Jinli BAI
1
;
Yujin QU
;
Fang SONG
;
Yanyan CAO
;
Ni JIA
;
Jia WANG
;
Yuwei JIN
;
Hong WANG
Author Information
1. 首都儿科研究所遗传研究室，北京 100020
- Keywords:
Muscular atrophy, spinal;
Molecular diagnostic techniques;
Survival motor neuron gene-1;
Survival motor neuron gene-2
- From:
Chinese Journal of Laboratory Medicine
2021;44(8):743-748
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore application status and development trend of spinal muscular atrophy (SMA) genetic diagnosis technology based on the national rare diseases registry system of China.Method:A total of 200 SMA children registered at the Capital Institute of Pediatrics from July 2016 to December 2018 were included in this retrospective cross-sectional survey. The basic data, clinical subtypes, genotypes, and related genetic testing information of SMA children were obtained by checking SMA registration information, genetic testing reports, and also by telephone follow-up. The patient number and the composition of different genetic diagnosis technologies were analyzed by the stratification of genetic testing at various time. The correlation between the proportion of genetic diagnosis technology and genetic testing time was analyzed with Pearson correlation analysis.Result:There were 3 SMA cases with incomplete data, the remaining 197 SMA cases were included in this study. There were 37 (18.8%), 115 (58.4%) and 45 (22.8%) patients with type Ⅰ, Ⅱ and Ⅲ SMA, respectively. There were 185 cases of SMN1 homozygous deletion (93.9%), and 12 cases with compound heterozygotes (6.1%). Seven SMA-related genetic technologies were used from 2004 to 2017. MLPA accounted for 54.1% (100/185) used approach, followed by PCR-RFLP and first-generation sequencing, which accounted for 22.7% (42/185) and 10.3% (19/185), respectively. Nine, 6, 5 and 4 cases were tested with AS-PCR, qPCR, WES and DHPLC, respectively (2.2%-4.9%). The proportion of MLPA increased gradually since 2010 ( r=0.95, P<0.05), while PCR-RFLP declined gradually since 2004 ( r=-0.99, P<0.05). No correlation was found between technology and testing time for other genetic testing technologies ( P>0.05). The proportion of quantitative genetic technologies (MLPA, qPCR and DHPLC) increased gradually since 2010 ( r=0.94, P<0.05), and qualitative genetic technologies (PCR-RFLP, first-generation sequencing, AS-PCR and WES) decreased gradually since 2004 ( r=-0.94, P<0.05). The duplication detection rates of homozygous deletion and compound heterozygous mutation were 12.4% (23/185) and 41.7% (5/12), respectively (χ 2=5.86, P<0.05). During 2008-2015, the proportion of "the reports of both copy numbers of SMN1 gene and SMN2 gene" increased from 56.8% (21/37) in 2008-2015 to 69.1% (56/81) in 2016-2017. Conclusion:Genetic diagnosis of SMA has gradually developed from qualitative detection technology to quantitative detection technology, such as MLPA and qPCR, in China. In more and more SMA quantitative test reports, quantitative results of SMN2 gene are also provided in addition to quantitative results of SMN1 gene.
