We read with interest the recent publication of Beer and Sahin-Toth1 reporting that exonic variants affecting pre-mRNA splicing contribute to the genetic burden in chronic pancreatitis. One particular variant, affecting the last nucleotide of exon 3 of the SPINK1 gene, c.194G>A, was found to cause an ∼80% reduction in SPINK1 mRNA expression as compared with the wild type in a minigene assay performed in human embryonic kidney 293T (HEK293T) cells. The SPINK1 sequence inserted into the minigene expression vector however comprised only exon 1, exon 2, exon 3, intron 3 and exon 4 of the four-exon gene.1 It should be noted that the potential effect of c.194G>A as a missense mutation (p.Arg65Gln) on protein function has previously been analysed; engineered expression of the full-length mutant coding sequence in Chinese hamster ovary cells and HEK293T cells showed a consistent 50%–60% reduction in protein secretion as compared with the wild type.2 ,3 We recently analysed the functional consequences of 24 SPINK1 intronic variants in relation to their associated mRNA splicing phenotypes4 ,5 by means of a full-gene splicing assay in which the full-length 7 kb SPINK1 genomic sequence (including all four exons plus all three introns of the gene) was cloned into the pcDNA3.1/V5-His-TOPO vector.6 This full-length gene expression system has already proved itself in practice by accurately representing the in vivo situation in the context …

中文翻译：

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体外和计算机证据反对 SPINK1 c.194G>A 变体对前 mRNA 剪接的显着影响

我们饶有兴趣地阅读了 Beer 和 Sahin-Toth1 最近发表的文章，该文章报道影响前 mRNA 剪接的外显子变异导致慢性胰腺炎的遗传负担。在人胚胎肾中进行的小基因测定中，发现与野生型相比，影响 SPINK1 基因外显子 3 最后一个核苷酸 c.194G>A 的一个特定变体导致 SPINK1 mRNA 表达降低约 80% 293T (HEK293T) 细胞。然而，插入小基因表达载体的 SPINK1 序列仅包含四外显子基因的外显子 1、外显子 2、外显子 3、内含子 3 和外显子 4。 1 应该注意的是，c.194G>A 作为先前已分析过蛋白质功能上的错义突变（p.Arg65Gln）；