Novel collagen VI mutations identified in Chinese patients with Ullrich congenital muscular dystrophy

Yan-Zhi Zhang, Dan-Hua Zhao, Hai-Po Yang, Ai-Jie Liu, Xing-Zhi Chang, Dao-Jun Hong, Carsten Bonnemann, Yun Yuan, Xi-Ru Wu, Hui Xiong

Beijing, China

Author Affiliations: Department of Pediatrics (Zhang YZ, Yang HP, Liu AJ, Chang XZ, Wu XR, Xiong H); Department of Neurology (Zhao DH, Hong DJ, Yuan Y), Peking University First Hospital, Beijing, China; Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke/NIH, USA (Bonnemann C)

Corresponding Author: Hui Xiong, MD, Department of Pediatrics, Peking University First Hospital, Beijing 100034, China (Tel: 0086-10-83573238; Fax: 0086-10-66530532; Email: xh_bjbj@163.com)

doi: 10.1007/s12519-014-0481-1

Background: We determined the clinical and molecular genetic characteristics of 8 Chinese patients with Ullrich congenital muscular dystrophy (UCMD).

Methods: Clinical data of probands were collected and muscle biopsies of patients were analyzed. Exons of COL6A1, COL6A2 and COL6A3 were analyzed by direct sequencing. Mutations in COL6A1, COL6A2 and COL6A3 were identified in 8 patients.

Results: Among these mutations, 5 were novel [three in the triple helical domain (THD) and 2 in the second C-terminal (C2) domain]. We also identified five known missense or in-frame deletion mutations in THD and C domains. Immunohistochemical studies on muscle biopsies from patients showed reduced level of collagen VI at the muscle basement membrane and mis-localization of the protein in interstitial and perivascular regions.

Conclusions: The novel mutations we identified underscore the importance of THD and C2 domains in the assembly and function of collagen VI, thereby providing useful information for the genetic counseling of UCMD patients.

Key words: collagen VI; in-frame; missense; triple helical domain; Ullrich congenital muscular dystrophy

World J Pediatr 2014;10(2):126-132