Department of Dermatology, Faculty of Medicine, Complejo Hospitalario Universitario, Santiago de Compostela, Spain.
Int J Dermatol. 2009 Nov;48(11):1195-7. doi: 10.1111/j.1365-4632.2009.04223.x.
The majority of cases of Lamellar ichthyosis (LI) are caused by mutations in the transglutaminase-1 (TGM1) gene. The mutations in the beta-barrel domains of the TGM1 gene are found very infrequently and several authors have suggested that these domains are not essential for the function of the enzyme. Other authors have postulated that mutations in these loci are pathogenic but they imply a less severe clinical picture of LI.
We report a patient with a severe phenotype of LI who had a homozygous mutation affecting the beta-barrel 2 domain of the TGM1.
This finding indicates that the integrity of beta-barrel domains is important for the correct function of the enzyme and that we are still far away from a consistent genotype-phenotype correlation.
大多数板层状鱼鳞病(LI)是由转谷氨酰胺酶-1(TGM1)基因突变引起的。TGM1 基因的β桶状结构域中的突变非常罕见,有几位作者认为这些结构域对于酶的功能不是必需的。其他作者推测这些部位的突变是致病的,但它们暗示了 LI 的临床表型较轻。
我们报告了一例具有严重 LI 表型的患者,其 TGM1 的β桶 2 结构域存在纯合突变。
这一发现表明β桶结构域的完整性对于酶的正确功能很重要,而且我们离一致的基因型-表型相关性还有很长的路要走。