cDNA analyses of CAPN3 enhance mutation detection and reveal a low prevalence of LGMD2A patients in Denmark
cDNA analyses of CAPN3 enhance mutation detection and reveal a low prevalence of LGMD2A patients in Denmark
复制标题
DOI：
10.1038/ejhg.2008.47
复制
发表时间：
2008-08-01
影响因子：
5.2
通讯作者：
Vissing, John
中科院分区：
文献类型：
--
作者：
Duno, Morten;Sveen, Marie-Louise;Vissing, John
钙蛋白酶病或肢带型肌营养不良2A型（LGMD 2A）通常被认为是隐性LGMD的最普遍形式，由CAPN 3基因突变引起。在我们的神经肌肉诊所的119名符合LGMD 2临床标准的患者中，基于蛋白质印迹结果，46名患者被怀疑患有LGMD 2A。这些患者中有4人在分子分析后显示出LGMD 2 I，而其余42名患者中有16名通过直接基因组测序和cDNA分析在CAPN 3中携带突变。在10例患者中，我们发现了两种突变等位基因。在另外三个中，在基因组水平上只能鉴定出一个杂合突变;然而，CAPN 3 cDNA分析证明突变等位基因的纯合性，表明存在以某种方式损害正确CAPN 3 RNA加工的未鉴定等位基因。在剩下的三名患者中，仅在基因组水平和全长CAPN 3 cDNA上鉴定出单个杂合突变。所有3例患者均表现出钙蛋白酶-3和LGMD 2A临床特征的高度异常蛋白质印迹。只有3名基因确诊的LGMD 2A患者来自丹麦，表明丹麦的患病率比其他欧洲国家低5 - 6倍。共鉴定了16种不同的CAPN 3突变，其中5种是新的。本研究证实了LGMD 2A患者CAPN 3的cDNA分析的价值，并表明钙蛋白病是丹麦LGMD的一种罕见原因。
Calpainopathy or limb-girdle muscular dystrophy type 2A (LGMD2A) is generally recognized as the most prevalent form of recessive LGMD and is caused by mutations in the CAPN3 gene. Out of a cohort of 119 patients fulfilling clinical criteria for LGMD2, referred to our neuromuscular clinic, 46 were suspected to have LGMD2A, based on western blot results. Four of these patients were shown to have LGMD2I upon molecular analysis, whereas 16 of the remaining 42 patients harbored mutations in CAPN3 by both direct genomic sequencing and cDNA analyses. In 10 patients, we identified both mutant alleles. In three other, only one heterozygous mutation could be identified on the genomic level; however, CAPN3 cDNA analyses demonstrated homozygosity for the mutant allele, indicating the presence of an unidentified allele that somehow compromise correct CAPN3 RNA processing. In the three remaining patients, only a single heterozygous mutation could be identified both at the genomic level and on full-length CAPN3 cDNA. All three patients exhibited a highly abnormal western blot for calpain-3 and clinical characteristics of LGMD2A. Only three of the genetically confirmed LGMD2A patients were of Danish origin, indicating a five- to sixfold lower prevalence in Denmark compared to other European countries. A total of 16 different CAPN3 mutations were identified, of which 5 were novel. The present study demonstrates the value of cDNA analysis for CAPN3 in LGMD2A patients and indicates that calpainopathy is an uncommon cause of LGMD in the Denmark.