Akiyama M, Tsuji-Abe Y, Yanagihara M, Nakajima K, Kodama H, Yaosaka M, Abe M, Sawamura D, Shimizu H
Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan.
Br J Dermatol. 2005 Jun;152(6):1353-6. doi: 10.1111/j.1365-2133.2005.06598.x.
Ichthyosis bullosa of Siemens (IBS, MIM 146800) is a unique congenital ichthyosis characterized by mild epidermal hyperkeratosis over flexural areas, blister formation and the development of superficially denuded areas of hyperkeratotic skin. It is clinically difficult to distinguish severe IBS from mild bullous congenital ichthyosiform erythroderma (BCIE, MIM 113800). In the current literature, 19 IBS families with keratin 2e (K2e) mutations have been reported, despite only five IBS families having been reported before the first identification of K2e mutation in 1994. We studied four patients from three Japanese IBS families. They had previously been misdiagnosed as having BCIE before the correct diagnosis was made after mutation detection. To detect the pathogenic mutations, we performed direct sequencing of the entire coding regions of KRT2E encoding K2e in the patients and healthy family members. K2e mutations, a 1469T-->C transition (L490P) and a 1477G-->A transition (E493K) within the conserved 2B helix termination motif of the rod domain were detected in the families and the definite diagnosis of IBS was made in the four cases. The present results indicate that IBS is not such a rare entity as was previously thought, and accurate diagnosis is now available by mutation analysis.
西门子大疱性鱼鳞病（IBS，MIM 146800）是一种独特的先天性鱼鳞病，其特征为屈侧皮肤轻度表皮角化过度、水疱形成以及角质化皮肤浅表剥脱区域的出现。临床上很难将严重的IBS与轻度大疱性先天性鱼鳞病样红皮病（BCIE，MIM 113800）区分开来。在当前文献中，已报道了19个携带角蛋白2e（K2e）突变的IBS家族，尽管在1994年首次鉴定出K2e突变之前仅报道过5个IBS家族。我们研究了来自三个日本IBS家族的四名患者。他们之前被误诊为患有BCIE，在检测到突变后才做出正确诊断。为了检测致病突变，我们对患者及其健康家庭成员中编码K2e的KRT2E的整个编码区进行了直接测序。在这些家族中检测到K2e突变，即在杆状结构域保守的2B螺旋终止基序内的一个1469T→C转换（L490P）和一个1477G→A转换（E493K），并对这四例患者做出了IBS的明确诊断。目前的结果表明，IBS并非如之前所认为的那样是一种罕见的疾病，现在通过突变分析可以进行准确诊断。
