Gedicke M M, Traupe H, Fischer B, Tinschert S, Hennies H C
Division of Dermatogenetics, Cologne Centre for Genomics, University of Cologne, Zülpicher Str. 47, 50674 Cologne, Germany.
Br J Dermatol. 2006 Jan;154(1):167-71. doi: 10.1111/j.1365-2133.2005.06995.x.
Loricrin keratoderma is an autosomal dominant palmoplantar keratoderma heterogeneous in clinical appearance. We report a family with diffuse ichthyosis and honeycomb palmoplantar keratoderma but no occurrence of pseudoainhums or autoamputations. All patients were born as collodion babies and displayed prominent knuckle pads. We identified the previously reported mutation 730insG in LOR, which elongates loricrin by 22 amino acids because of delayed termination. As pseudoainhums are missing in all patients of the family reported, we propose two compulsory features of loricrin keratoderma: (i) honeycomb palmoplantar keratoderma and (ii) diffuse ichthyosiform dermatosis. Therefore we suggest that the condition should be described clinically as 'honeycomb palmoplantar keratoderma with ichthyosis'. Furthermore, we have assessed the amounts of transcript of LOR using pyrosequencing. This revealed an equal expression of mutant and wild-type alleles of LOR in an affected individual. These findings further underline the gain-of-function theory for mutant LOR in loricrin keratoderma.
兜甲蛋白角化病是一种常染色体显性遗传性掌跖角化病，临床表现具有异质性。我们报告了一个患有弥漫性鱼鳞病和蜂窝状掌跖角化病但未出现假阿洪病或自行截肢情况的家系。所有患者出生时均为胶样婴儿，并表现出明显的指节垫。我们在兜甲蛋白（LOR）基因中鉴定出先前报道的730insG突变，该突变由于终止延迟使兜甲蛋白延长了22个氨基酸。鉴于所报道家系的所有患者均未出现假阿洪病，我们提出兜甲蛋白角化病的两个必备特征：（i）蜂窝状掌跖角化病和（ii）弥漫性鱼鳞病样皮肤病。因此，我们建议临床上应将该病描述为“伴有鱼鳞病的蜂窝状掌跖角化病”。此外，我们使用焦磷酸测序法评估了LOR的转录本数量。结果显示，在一名受累个体中，LOR的突变等位基因和野生型等位基因表达量相等。这些发现进一步强调了突变型LOR在兜甲蛋白角化病中的功能获得理论。
