Three novel mutations of the FBN1 gene in Chinese children with acromelic dysplasia.

Abstract

Geleophysic dysplasia (GD), acromicric dysplasia (AD) and Weill-Marchesani syndrome (WMS) are rare disorders with overlapping characteristics, such as short stature, short hands and feet, joint limitations, skin thickening, mild facial anomalies, normal intelligence and abnormal skeletal symptoms, with GD distinct by progressive cardiac valvular thickening and WMS distinct by microspherophakia and ectopia lentis. Mutations in FBN1 gene have been identified in AD, GD and WMS patients. By targeted next-generation sequencing of skeletal dysplasia-related genes, including FBN1 and ADAMTSL2, three novel missense mutations, c.5189A>T (p.N1730I), c.5198G>T (p.C1733F), c.5243G>T (p.C1748F), and one known mutation c.5198G>A (p.C1733Y) of FBN1 gene were identified in four probands, respectively. Clinically, p.C1733Y was associated with GD, as reported previously, as well as the novel p.N1730I, whereas p.C1733F and p.C1748F were associated with AD and WMS. Interestingly, different mutations at the same codon (p.C1733Y and p.C1733F) were associated with different phenotypes (GD and AD, respectively). However, the mutations p.C1748F and p.C1748R were associated with WMS. Our data support the importance of TGFβ-binding protein-like domain 5 of FBN1 protein in pathogenicity of acromelic dysplasia, and expands the genotype/phenotype relations of these rare forms of fibrilliopathies.