Department of Medical Genetics, University of Ottawa, Ottawa, Ontario, Canada.
Am J Med Genet A. 2013 May;161A(5):1148-53. doi: 10.1002/ajmg.a.35827. Epub 2013 Mar 26.
Autosomal recessive cutis laxa (ARCL) is a clinically and genetically heterogeneous group of disorders characterized by loose, inelastic skin and variable systemic involvement and severity. Mutations in the FBLN4 gene are associated with ARCL1B. Fibulin-4 is important in elastic fiber formation and smooth muscle cell differentiation. We describe herein an 8-year-old boy who presented with severe aortic root dilatation and arterial tortuosity at 1 year of age which required surgical repair. His parents were consanguineous and there was a family history of three brothers who died early in life with an unknown type of connective tissue disorder in the 1960s. Both parents of the patient reported here were related to these three boys. We used a homozygosity mapping strategy with a 900K SNP array and identified FBLN4 as a candidate gene in an extended region of homozygosity. We sequenced this gene in the patient and identified a homozygous non-synonymous mutation at c.376G>A (p.Glu126Lys) in exon 5 that was predicted to be damaging. ARCL1B has most typically been associated with early demise but our report suggests that long-term survival is possible. With this longer term survival we are learning more about the natural history of this disorder, which includes baroreceptor reflex failure and low bone mineral density in this patient.
常染色体隐性皮肤松弛症(ARCL)是一组临床和遗传异质性疾病,其特征为皮肤松弛、无弹性,且伴有不同程度的全身性受累。FBLN4 基因突变与 ARCL1B 相关。纤维连接蛋白-4 在弹性纤维形成和平滑肌细胞分化中起重要作用。本文报道了 1 例 8 岁男孩,1 岁时因严重主动脉根部扩张和动脉迂曲而接受手术修复。患儿父母近亲结婚,其家族史中有 3 个兄弟,他们于 20 世纪 60 年代在生命早期死于一种未知类型的结缔组织疾病。本例患儿的父母均与这 3 个男孩有关。我们采用了一种基于全基因组单体型分析的连锁分析策略,并在一个扩展的纯合区域中确定了 FBLN4 作为候选基因。我们对该基因进行测序,在 5 号外显子中发现了 c.376G>A(p.Glu126Lys)的纯合错义突变,该突变被预测为有害突变。ARCL1B 通常与早期死亡相关,但我们的报告表明,长期生存是可能的。随着患者的长期生存,我们对该疾病的自然史有了更多的了解,包括该患者的压力感受器反射衰竭和低骨密度。