Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Bünteweg 17, 30559 Hannover, Germany.
Department of Pediatrics, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany.
Nutrients. 2019 Sep 25;11(10):2290. doi: 10.3390/nu11102290.
Congenital sucrase-isomaltase deficiency (CSID) is an autosomal recessive disorder of carbohydrate maldigestion and malabsorption caused by mutations in the sucrase-isomaltase (SI) gene. SI, together with maltase-glucoamylase (MGAM), belongs to the enzyme family of disaccharidases required for breakdown of -glycosidic linkages in the small intestine. The effects of homozygote and compound heterozygote inheritance trait of SI mutations in CSID patients have been well described in former studies. Here we propose the inclusion of heterozygote mutation carriers as a new entity in CSID, possibly presenting with milder symptoms. The hypothesis is supported by recent observations of heterozygote mutation carriers among patients suffering from CSID or patients diagnosed with functional gastrointestinal disorders. Recent studies implicate significant phenotypic heterogeneity depending on the character of the mutation and call for more research regarding the correlation of genetics, function at the cellular and molecular level and clinical presentation. The increased importance of SI gene variants in irritable bowel syndrome (IBS) or other functional gastrointestinal disorders FGIDs and their available symptom relief diets like fermentable oligo-, di-, mono-saccharides and polyols FODMAPs suggest that the heterozygote mutants may affect the disease development and treatment.
先天性蔗糖-异麦芽糖酶缺乏症（CSID）是一种常染色体隐性遗传疾病，由于蔗糖-异麦芽糖酶（SI）基因突变，导致碳水化合物消化和吸收不良。SI 与麦芽糖酶-葡糖苷酶（MGAM）一起，属于需要在小肠中分解 α-糖苷键的双糖酶家族。以前的研究已经很好地描述了 CSID 患者中 SI 突变的纯合子和复合杂合子遗传特征的影响。在这里，我们提出将杂合子突变携带者纳入 CSID 的一个新实体，其可能表现出更轻微的症状。这一假设得到了最近在 CSID 患者或功能性胃肠疾病患者中观察到杂合子突变携带者的支持。最近的研究表明，突变的特征取决于表型的显著异质性，并呼吁对遗传、细胞和分子水平的功能以及临床表现之间的相关性进行更多的研究。SI 基因变异在肠易激综合征（IBS）或其他功能性胃肠疾病 FGIDs 中的重要性日益增加，以及它们可用的缓解症状饮食，如可发酵的寡糖、二糖、单糖和多元醇（FODMAPs），表明杂合子突变可能会影响疾病的发展和治疗。
