Spontaneous clinical remission of Nagashima-type palmoplantar keratoderma in a patient of Korean descent with a heterozygous SERPINB7 mutation

Nagashima-type palmoplantar keratoderma (NPPK) is an autosomal recessive form of diffuse palmoplantar keratoderma (PPK) characterized by thickening and redness of palms and/or soles. In this report, we describe a female patient of Korean descent who had clinical remission of her adult-onset NPPK. To our knowledge, she is the first reported heterozygous SERBINB7 mutation carrier to present with classic NPPK who achieved spontaneous clinical remission.     

长岛型掌跖角化病二例SERPINB7基因突变研究

目的 报告2例长岛型掌跖角化病,确定其致病基因突变。 方法 收集患者及其父母外周血和临床资料,提取基因组DNA,PCR扩增SERPINB7基因8个外显子及其侧翼序列,对扩增产物进行DNA测序以查找基因突变位点,并以200例无关健康人DNA作为对照进行扩增测序。 结果 2例患者均存在SERPINB7基因c.796C > T纯合突变,导致编码蛋白质第266位氨基酸出现终止改变（p.R266*）,其父母均为c.796C > T杂合突变,而无关健康对照未发现上述突变。 结论 SERPINB7基因的c.796C > T突变可能是引起2例患者长岛型掌跖角化病的原因。     

长岛型掌跖角化病一家系丝氨酸蛋白酶抑制剂B7基因的突变分析

目的:对一家系长岛型掌跖角化病(NPPK)丝氨酸蛋白酶抑制剂B7(SERPINB7)基因突变进行分析。方法:采用聚合酶链式反应扩增SERPINB7基因所有的外显子及其邻近的剪切点并进行直接测序。结果:一家系成员5人,患者1人。先证者,男,23岁,先证者及其母亲均检测到SERPINB7纯合突变c.796CT(p.Arg266Ter),该突变导致SERPINB7基因编码的蛋白第266位氨基酸由精氨酸变为终止密码。先证者父亲、两位弟弟及100例正常对照中均未检测到SERPINB7基因突变。结论:SERPINB7 c.796CT(p.Arg266Ter)基因纯合突变可能是该例NPPK患者的致病原因。     

A case of spontaneous mutation in the keratin 9 gene associated with epidermolytic palmoplantar keratoderma

Epidermolytic palmoplantar keratoderma appears to be due to defects in keratin 9, the palmoplantar specific type 1 keratin. We report a case of spontaneous mutation, a C to T transition at codon 162, resulting in an arginine to tryptophan substitution in the 1 A region of the alpha helical rod domain of keratin 9. This provides further evidence that this codon is an important spot for mutation in keratin 9.     

Clinically specific type of focal palmoplantar keratoderma with sensorineural deafness: an entity

A case of focal palmoplantar keratoderma with associated sensorineural deafness is reported. The palmoplantar keratoderma was sharply marginated by geometric borders, spared the plantar arch and was accompanied by marked hyperkeratosis of palmar flexural creases. This syndrome, consisting of a very particular type of palmoplantar keratoderma associated with sensorineural deafness, appears to be distinctive enough to be considered as a clinical entity.     

A novel mutation of keratin 9 in a large Chinese family with epidermolytic palmoplantar keratoderma

BACKGROUND: Epidermolytic palmoplantar keratoderma (EPPK) is an autosomal dominant inherited skin disorder characterized by diffuse yellow thickening of the skin of the palms and soles, sharply bordered with erythematous margins. Histologically and ultrastructurally, EPPK presents cytolysis of keratinocytes and abnormal aggregation of tonofilaments in the suprabasal layers of the epidermis. To date, 15 different mutations of the keratin 9 gene (KRT9) have been demonstrated to cause most cases of EPPK. OBJECTIVES: To identify the KRT9 mutation in a large Chinese family with EPPK. METHODS: Denaturing high-performance liquid chromatography (DHPLC), DNA sequencing and allele-specific polymerase chain reaction (AS-PCR) were used to screen exon 1 of the KRT9 gene for sequence variations. RESULTS: The DHPLC elution profiles of the DNA fragments amplified from the affected samples differed from those obtained from unaffected individuals, indicating that a sequence variation existed within the analysed fragment of KRT9. DNA sequencing revealed a novel insertion-deletion mutation in the exon 1 of KRT9, 497delAinsGGCT, resulting in the change of tyrosine(166) to tryptophan and leucine (Y166delinsWL). AS-PCR confirmed the mutation was not a common polymorphism. CONCLUSIONS: The results suggest the molecular basis of EPPK in this Chinese family and provide further evidence that mutations in the helix initiation motif of keratin 9 underlie Chinese EPPK.     

表皮松解性掌跖角皮症一家系KRT9基因新突变

目的:检测表皮松解性掌跖角皮症一家系患者角蛋白9(KRT9)基因突变。方法:收集家系成员的临床资料和血样,提取家系中4例患者和3名正常人及50名与本家系无关的正常对照外周血DNA,采用PCR技术扩增KRT9基因所有编码区并进行测序,分别检测家系中的突变情况。结果:该家系中所有患者均存在KRT9基因错义突变(c.484TC),导致第162位密码子由TCT(丝氨酸)转变为CCT(脯氨酸)(p.S162P),家系中3名正常个体和50名健康对照均未发现上述突变。结论:KRT9基因c.484TC错义突变是导致该家系发生表皮松解性掌跖角皮症的遗传基础。