Argyropoulou Zoe, Liu Lu, Ozoemena Linda, Branco Claudia C, Senra Raquel, Reis-Rego Ângela, Mota-Vieira Luisa
Molecular Genetics and Pathology Unit, Hospital of Divino Espírito Santo of Ponta Delgada, EPER, Av. D. Manuel I, 9500-370, Ponta Delgada, São Miguel Island, Azores, Portugal.
The National Diagnostic EB Lab, St Thomas' Hospital, London, UK.
BMC Dermatol. 2018 Jan 20;18(1):1. doi: 10.1186/s12895-018-0069-x.
Epidermolysis bullosa simplex with muscular dystrophy (EBS-MD; OMIM #226670) is an autosomal recessive disease, characterized mainly by skin blistering at birth or shortly thereafter, progressive muscle weakness, and rarely by alopecia. EBS-MD is caused by mutations in the PLEC gene (OMIM *601282), which encodes plectin, a structural protein expressed in several tissues, including epithelia and muscle. We describe a patient affected with EBS-MD and diffuse alopecia in which we identified a novel pathogenic mutation by PCR amplification of all coding exons and exon-intron boundaries of PLEC gene, followed by bidirectional Sanger sequencing.
The patient, a 28-year-old female and only child of consanguineous healthy parents, was born after uneventful pregnancy. At 2 days of age, she developed skin and oral mucosal blistering, accompanied by voice hoarseness. On physical examination as an adult, we observed diffuse non-scarring alopecia on the scalp, onychodystrophy (pachyonychia) in all 20 nails, dental decay, mild dysphonia, and severe muscle atrophy mainly affecting the extremities. Neurological examination showed profoundly diminished reflexes. Mutation analysis revealed the patient to be homozygous for the novel PLEC nonsense mutation - c.7159G > T (p.Glu2387*) - located in exon 31. Thismutation predicts the lack of expression of the full-length plectin isoform.
The present case appears to be the second association of EBS-MD with diffuse alopecia, both cases having different mutations involving PLEC exon 31. It remains to be elucidated whether diffuse alopecia results from PLEC mutations and/or from environmental factors.
单纯型大疱性表皮松解症伴肌肉萎缩(EBS-MD;OMIM #226670)是一种常染色体隐性疾病,主要特征为出生时或出生后不久出现皮肤水疱、进行性肌肉无力,少数情况下伴有脱发。EBS-MD由PLEC基因(OMIM *601282)突变引起,该基因编码网蛋白,这是一种在包括上皮和肌肉在内的多种组织中表达的结构蛋白。我们描述了一名患有EBS-MD和弥漫性脱发的患者,通过对PLEC基因的所有编码外显子和外显子-内含子边界进行PCR扩增,随后进行双向桑格测序,我们鉴定出了一种新的致病突变。
该患者为一名28岁女性,是近亲结婚的健康父母的独生女,孕期正常。出生2天时,她出现皮肤和口腔黏膜水疱,并伴有声音嘶哑。成年后体检发现,她头皮有弥漫性非瘢痕性脱发,20个指甲均有甲营养不良(厚甲症),有龋齿、轻度发音障碍,以及主要影响四肢的严重肌肉萎缩。神经学检查显示反射明显减弱。突变分析显示,该患者在位于第31外显子的新的PLEC无义突变 - c.7159G>T(p.Glu2387*)上为纯合子。该突变预示全长网蛋白异构体缺乏表达。
本病例似乎是EBS-MD与弥漫性脱发的第二次关联,两例病例涉及PLEC第31外显子的突变不同。弥漫性脱发是否由PLEC突变和/或环境因素引起仍有待阐明。