| Objectives:1. Clinical features of myotonic dystrophy type 1 (DM1) was analyzed and summarized, to improve the understanding the diverse manifestations of DM1.2. To investigate the frequency distribution of CTG repeats of normal DMPK alleles in a group of Northern Chinese Hans.3. To confirm the relative qualification of miRNAs in skeletal muscles from DM1 patients and controls.Methods:1. The clinical data of 85 patients who were diagnosed genetically as DM1 in 2009 to 2015 were studied retrospectively.2. One hundred and ninety-seven unrelated Chinese Han individuals from northern China (62 diagnosed with DM1 by genetic tests, and 135 healthy individuals) were studied. We evaluated the frequencies of CTG repeat lengths in the normal DMPK genes by running the PCR products through capillary electrophoresis and subsequently analyzing the data on GeneMapper 3.7.3.16 muscle specimens as experimental group were abtained by biopsy from different DM1 patients and 16 normal controls were harvested from patients through orthopedic surgery. miR-196a, miR-182, miR-451, miR-200c, miR-146a, miR-133a, miR-1, miR-206, CELF1, CELF2, MBNL1 and MYF5 were detected using real time PCR, TargetScan 7.0 was used to predict the possible targets of miRNAs.Results:1.47 of 85 patients (52 men) has a positive family history. Muscle weakness was the most common initial syndrome. The incidence of myotonia, muscle weakness and amyotrophy which involved muscles of face, neck and distal extremities preferentially were 95.56%,93.33% and 75.56% respectively, the course of DM1 was correlated with the degree of MIRS and the involvement of multisystem..2. A total of 19 (CTG)n alleles were observed with a range of 5 to 32 CTG repeats on 332 normal chromosomes. The most common allele was 5 CTG repeats (24.4%), followed by alleles with 12 (22.9%),13 (18.7%),11 (17.8%) and 14 (5.1%) repeats. Importantly, besides the bimodal distribution with peaks at 5 and 11-14 repeats, another minor peak at 8 (3.0%) repeats was observed. Nine alleles (2.7%) had CTG repeats larger than 18.3. miR-196a, miR-182, miR-146a, miR-200c were down-regulated in DM1; CELF2 and MYF5 were wp-regulated in DM1. miR-1, miR-133, miR-206, miR-451, CELF1 and MBNL1 were normally expressed in DM1. TargetScan and Dual-Luciferase Reporter assay analysis showed CELF2 were target of miR-182 and miR-196a.Conclusions:1. Characteristics of classic DM1 has insidious onset in young and middle-aged patients. Positive family history is important to diagnosis but not necessary. Cataracts are most common except muscular involvement. The higher degree of MIRS was related to longer course of disease and higher possibility of multisystem involvement.2. Polymorphism of DMPK gene in Northern Chinese people were different from that of people from Southern China and the epidemiological characteristics of DM1 need further reaserches based on lager samples from more areas and multi-ethnic groups.3. Several miRNAs were misexpression in DM1 and miR-182 and miR-196a might play a role in pathogenesis of DM1 by regulating the expression of CELF2... |
PDF Full Text Request