Li Dongxiao, Dong Hui, Zheng Hong, Song Jinqing, Li Xiyuan, Jin Ying, Liu Yupeng, Yang Yanling
Department of Pediatrics, Peking University First Hospital, Beijing, China.
Department of Pediatrics, The First Hospital of Henan University of Traditional Chinese Medicine, China.
Eur J Med Genet. 2017 Dec;60(12):685-689. doi: 10.1016/j.ejmg.2017.09.003. Epub 2017 Sep 14.
Geleophysic dysplasia, belonging to the group of acromelic dysplasia, is a rare genetic disease. Two genes, FBN1 and ADAMTSL2, were known to be linked to this disorder. The disorder presents as extreme short stature, short limbs, small hands and feet, stubby fingers and toes, joint stiffness, toe walking, skin thickening, progressive cardiac valvular thickening and characteristic facial features, including a round face with full cheeks. Here, we report the first Chinese case with geleophysic dysplasia type 1 based on clinical and genetic features. The boy was admitted because of severe physical growth retardation and mild motor retardation. Comprehensive medical evaluations were performed including metabolic studies, endocrine function examination, bone X-rays and echocardiography. Much delayed bone age and geleophysic dysplasia were found. Targeted next-generation sequencing was used to detect genetic mutations associated with skeletal dysplasia. Sanger sequencing was used to confirm the mutations in the patient. PCR amplification, cloing, and sequencing was used to determine the de novo mutation origin. Two compound heterozygous mutations were confirmed in the ADAMTSL2 gene of the patient. The c.340G > A (p.Glu114Lys) mutation was a de novo heterozygous mutation, and our results suggested that it was located on the paternal allele. While the c.234-2A > G inherited from his mother was a novel pathogenic heterozygous splicing mutation. Growth hormone deficiency had been observed in the patient. His growth velocity was improved by growth hormone supplementation. In conclusion, we have identified a novel splicing mutation of ADAMTSL2 carried by a Chinese boy with geleophysic dysplasia type 1. The patient was treated effectively with growth hormone supplementation.
脂肪代谢性骨发育不良属于肢端发育不良组,是一种罕见的遗传性疾病。已知有两个基因,即FBN1和ADAMTSL2与这种疾病有关。该疾病表现为极度身材矮小、四肢短小、手足小、手指和脚趾粗短、关节僵硬、踮足行走、皮肤增厚、进行性心脏瓣膜增厚以及特征性面部特征,包括圆脸且脸颊丰满。在此,我们基于临床和基因特征报告首例1型脂肪代谢性骨发育不良的中国病例。该男孩因严重身体发育迟缓及轻度运动发育迟缓入院。进行了全面的医学评估,包括代谢研究、内分泌功能检查、骨骼X线检查和超声心动图检查。发现骨龄严重延迟及脂肪代谢性骨发育不良。采用靶向二代测序检测与骨骼发育不良相关的基因突变。采用桑格测序法确认患者的突变情况。采用聚合酶链反应(PCR)扩增、克隆和测序来确定新发突变的起源。在患者的ADAMTSL2基因中确认了两个复合杂合突变。c.340G>A(p.Glu114Lys)突变是一个新发杂合突变,我们的结果表明它位于父本等位基因上。而从其母亲遗传的c.234 - 2A>G是一个新发现的致病性杂合剪接突变。在该患者中观察到生长激素缺乏。补充生长激素后其生长速度有所改善。总之,我们鉴定出一名患有1型脂肪代谢性骨发育不良的中国男孩携带的ADAMTSL2基因新剪接突变。该患者通过补充生长激素得到有效治疗。