Clinical and genetic features of limb-girdle muscular dystrophy type 1B: a case report.
- Author:
Xin-Xiu YU
1
;
Jing-Zi ZHONG
;
Hong-Lin GUAN
;
Min ZHANG
;
Dan LAN
Author Information
1. Department of Pediatrics, First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China. land6785@163.com.
- Publication Type:Case Reports
- MeSH:
Amino Acid Sequence;
Humans;
Lamin Type A;
Muscular Dystrophies, Limb-Girdle;
Mutation
- From:
Chinese Journal of Contemporary Pediatrics
2018;20(12):1015-1019
- CountryChina
- Language:Chinese
-
Abstract:
This article reports a case of limb-girdle muscular dystrophy type 1B (LGMD1B) caused by a novel splicing heterozygous mutation in the LMNA gene. The proband presented with progressive aggravation of weakness in walking. There was no atrophy of the scapular muscles and the lower-extremity proximal muscles, with normal muscle tension of the extremities, grade 4 muscle strength in the upper and lower extremities, and positive Gower sign. The level of creatine kinase was 779 U/L. Muscle hematoxylin-eosin staining showed muscular dystrophy, and there was no significant reduction in the expression of Lamin A protein. Second-generation sequencing revealed a novel splicing heterozygous mutation, c.810+2T>C, in the LMNA gene, while this locus was normal in his parents. GERP++RS software predicted that the mutation site was highly conservative. Human Splice Finder and Spliceman software predicted that the mutation might be a pathogenic mutation. ExPASy software predicted that the new amino acid sequence became shorter. There were two sequences of mRNA in the patient's muscle: one was the normal sequence, which accounted for 92.2%; the other was partial intron 4 retention, which was the abnormal splice variant accounting for 7.8%. LGMD1B is a type of autosomal dominant inherited myopathy caused by a mutation in the LMNA gene located on the autosomal 1q22. This study extends the mutation spectrum of the LMNA gene and provides help to the diagnosis of LGMD1B.
