Adenine ; Animals ; Gene Editing ; Mice ; Mutation ; Myotonic Dystrophy ; genetics ; Rats

Myotonic dystrophy type 1 (DM1, OMIM 160900) is a rare autosomal dominant hereditary disease. A case of DM1 patient with early onset diabetes and decreased muscle strength was treated in the Department of Endocrinology, Third Xiangya Hospital, Central South University. The peripheral blood of the patient was collected to extract DNA for gene detection. It was found that the triple nucleotide CTG repeat in the 3'-untranslated region (3'-UTR) of the dystrophia myotonica protein kinase (DMPK) gene was more than 100 times, and the diagnosis of DM1 was clear. For diabetes patients with multiple system abnormalities such as muscle symptoms, attention should be paid to the screening of DM1, a rare disease.
Humans ; Myotonic Dystrophy/genetics* ; Abnormalities, Multiple ; Hospitals ; Universities ; Diabetes Mellitus

OBJECTIVETo observe trinucleotide repeat number, (CTG)n in the 3'-untranslated region of the myotonic protein kinase (MTPK) gene in a clinically suspected woman with myotonic dystrophy (DM) family history and her abortus, in order to confirm the necessity of exerting antenatal examination in patients or suspected individuals with DM family history.

METHODSLong Expand Template polymerase chain reaction (PCR) system was used to analyze CTG trinucleotide repeat numbers located in the 3' untranslated region of MTPK on chromosome 19q13.2-3 in both peripheral white cells and muscles of the suspected mother and the other two DM patients in the family. The tissues of her abortus and blood of a health woman were detected, too.

RESULTSCTG repeats in both peripheral white cells and muscles of the suspected mother and the tissue of abortus were higher than normal range of CTG repeat number. There is no significant difference between blood and muscle samples. High CTG repeats were detected in blood and muscles of the typical DM members in the family, but in the blood sample of control, CTG repeats is normal.

CONCLUSIONCTG trinucleotide analyses and antenatal examination should be done in pregnant with a DM family history, in order to reduce the birth rate of DM offspring.

Adult ; DNA ; analysis ; Female ; Fetus ; metabolism ; Humans ; Myotonic Dystrophy ; diagnosis ; genetics ; Prenatal Diagnosis ; Trinucleotide Repeats

OBJECTIVETo carry out clinical and genetic analysis for three pedigrees affected with myotonic dystrophy type 1 (DM1).

METHODSThree probands with clinically diagnosed DM and their familial members were recruited. Clinical data of the patients including clinical manifestations, electrocardiogram (ECG), and electromyogram (EEG) was collected.

RESULTSThe clinical symptoms of all probands have progressed slowly and included myotonia, muscle weakness and muscle atrophy as the main manifestations. Disorders of other systems have included cataract, arrhythmia, alopecia, sexual dysfunction, and cognitive impairment. The EEG of the probands showed characteristic myotonia discharges. Genetic analysis revealed over 50 CTG repeats at the 3' end of the DMPK gene in all three probands.

CONCLUSIONDM1 is a complex hereditary disorder involving multiple systems and overlaps with other diseases. In addition to clinical symptoms and EEG, genetic testing can facilitate its diagnosis at early stages.

Adult ; Electrocardiography ; Electroencephalography ; Female ; Genetic Testing ; Humans ; Male ; Middle Aged ; Myotonic Dystrophy ; genetics ; physiopathology ; Pedigree

OBJECTIVETo investigate the clinical manifestations and to make genetic analysis in a pedigree with myotonic dystrophy disease.

METHODSThe proband and available family members were identified by neurological examination. The clinical manifestation of 8 patients (including the proband) was analyzed; the electromyographic data of 5 patients were compared with 6 other family members. Blood samples were obtained from the 7 patients of the family (excepting II6). DM(1) and DM(2) gene were amplified by PCR, tested by agarose electrophoresis, then analyzed by genetic analyzer.

RESULTSMyotonia and muscle weakness were the main manifestations associated with heart block (7/8) and cataract(6/7). Electromyologram showed myopathic abnormalities not only in patients but also in other members of the family (5/6). The CTG repeats in DM1 and CCTG repeats in DM2 were all in normal range.

CONCLUSIONThere likely to be new mutants in this DM pedigree and further study is needed.

Adult ; Base Sequence ; Female ; Humans ; Male ; Microsatellite Repeats ; genetics ; Molecular Sequence Data ; Myotonic Dystrophy ; genetics ; Myotonin-Protein Kinase ; Pedigree ; Polymerase Chain Reaction ; methods ; Protein-Serine-Threonine Kinases ; genetics

OBJECTIVE: To analyze the clinical, familial and hereditary features of myotonic dystrophy to improve the knowledge and provide molecule evidence for gene diagnosis and prenatal diagnosis of myotonic dystrophy or dystrophia myotonia (DM) families. METHODS: Clinical data of 2 DM families were collected based on the probands. The number of trinucleotide CTG repeat in the 3' untranslated region of myotonic dystrophy protein kinase (DMPK) gene on chromosome 19 was determined by DNA sequence and repeat fragment. RESULTS: Except for 1 subclinical patient, another 5 patients progressed slowly with the features of myotonic muscular weakness and atrophy. One patient had hatchet face, 1 had cataract and diabetes mellitus, and the other 3 were bald. Electromyologram showed 3 patients had myotonic discharge and myopathic abnormalities. The number of trinucleotide CTG repeat in the 3' untranslated region of DMPK gene of 5 patients exceeded 50. CONCLUSION DM can be anticipated. Gene analysis can verify the disease and identify subclinical patients. It helps to prevent the DM births by hereditary consultation performing prenatal diagnosis.
Adolescent ; Adult ; Female ; Humans ; Male ; Myotonic Dystrophy ; diagnosis ; genetics ; Myotonin-Protein Kinase ; Pedigree ; Polymerase Chain Reaction ; methods ; Protein-Serine-Threonine Kinases ; genetics ; Trinucleotide Repeats

BACKGROUNDMyotonic dystrophy type 1 (DM1) is an autosomal dominant multisystem disease caused by abnormal expansion of cytosine-thymine-guanine (CTG) repeats in the myotonic dystrophy protein kinase gene. The clinical manifestations of DM1 are multisystemic and highly variable, and the unstable nature of CTG expansion causes wide genotypic and phenotypic presentations, which make molecular methods essential for the diagnosis. So far, very few studies about molecular diagnosis in Chinese patients with DM1 have been reported. Therefore, we carried out a study using two different methods in molecular diagnosis to verify the validity in detecting CTG expansion in Chinese patients showing DM signs.

METHODSA total of 97 Chinese individuals were referred for molecular diagnosis of DM1 using conventional polymerase chain reaction (PCR) accompanied by Southern blotting and triplet primed PCR (TP-PCR). We evaluated the sensitivity and limitation of each method using percentage.

RESULTSBy conventional PCR 65 samples showed only one fragment corresponding to the normal allele and 62 out of them were correctly diagnosed as DM1 by TP-PCR and three homologous non-DM1 samples were ruled out; Southern blotting analysis successfully made 13 out of 16 correct diagnoses with a more sensitivity using α-(32)P-labeled probes than dig-labeled probes.

CONCLUSIONMolecular analysis is necessary for the diagnosis of DM1 and TP-PCR is a reliable, sensitive, and easily performed method in molecular diagnosis which is worthy to be popularized.

Adult ; Aged ; Blotting, Southern ; Female ; Humans ; Male ; Middle Aged ; Molecular Diagnostic Techniques ; methods ; Myotonic Dystrophy ; diagnosis ; genetics ; Polymerase Chain Reaction ; Sensitivity and Specificity ; Young Adult

Congenital myotonic dystrophy type 1 (DM1) presents severe generalized weakness, hypotonia, and respiratory compromise after delivery with high mortality and poor prognosis. We presented a congenital DM1 of premature twins in the 30th week of gestation. These twins were conceived by in vitro fertilization (IVF). Both babies presented apnea and hypotonia and had characteristic facial appearance. They were diagnosed DM1 by genetic method. They were complicated by chylothorax and expired at 100 and 215 days of age, respectively. Mother was diagnosed DM1 during the evaluation of babies. This is the first report on congenital DM1 which accompanied the chylothorax. More investigation on the association with chylothorax and congenital DM1 is recommended. With a case of severe neonatal hypotonia, congenital DM1 should be differentiated in any gestational age. Finally, since DM1 is a cause of infertility, we should consider DM1 in infertility clinic with detailed history and physical examination.
Adult ; Apnea/etiology ; Blotting, Southern ; Chylothorax/complications ; Female ; Fertilization in Vitro ; Humans ; Infant, Newborn ; Infant, Premature ; Microsatellite Repeats/genetics ; Muscle Hypotonia/etiology ; Myotonic Dystrophy/complications/*diagnosis/radiography ; Twins

OBJECTIVETo establish an efficient method which can be easily used for detecting CTG trinucleotide repeats in myotonic dystrophy type 1 (DM1).

METHODSTri-primer polymerase chain reaction (TP-PCR) combined with electropherogram was used to detect CTG repeats in the 3'-untranslated region of DMPK gene. Twenty non-related DM1 patients and 24 healthy controls were selected.

RESULTSAll patients were found to have carried pathologic alleles containing more than 100 CTG repeats, while the healthy controls have carried 5-37 CTG repeats.

CONCLUSIONTP-PCR combined with electropherograms may provide a highly sensitive, specific and accurate method which is less time-consuming and easier to perform for the detection of pathologic alleles in DM1 patients.

3' Untranslated Regions ; Adolescent ; Adult ; Alleles ; Case-Control Studies ; Female ; Humans ; Male ; Middle Aged ; Myotonic Dystrophy ; genetics ; Trinucleotide Repeats ; Young Adult

OBJECTIVETwo genetic loci are associated with the myotonic dystrophy (DM) phenotype: DM1 DMPK on chromosome 19, and DM2 ZNF9 on chromosome 3. The aim of this study was to investigate the molecular genetics of a pedigree with DM.

METHODSIn twenty-six individuals from a family with DM, the CTG repeats in DMPK and CCTG repeats in ZNF9were evaluated genetically, using Long Expand trade mark Template polymerase chain reaction (PCR), Southern blotting and genomic scanning.

RESULTSThe numbers of CTG and CCTG repeat were all in normal range. There was no significant difference between the CTG repeat size in DMPK gene and that 4 years later from the same individual. The Lod score values with short tandem repeats STR markers chosen in 19q and 3q were all smaller than 1, which suggested that no STR marker was linked with this DM family.

CONCLUSIONThere might be some other mutant in this DM pedigree. Further study should be done to find the genetic basis of this pedigree.

Adolescent ; Adult ; Blotting, Southern ; Child ; Female ; Humans ; Male ; Microsatellite Repeats ; genetics ; Middle Aged ; Myotonic Dystrophy ; genetics ; Myotonin-Protein Kinase ; Pedigree ; Polymerase Chain Reaction ; Protein-Serine-Threonine Kinases ; genetics ; RNA-Binding Proteins ; genetics ; Trinucleotide Repeats ; genetics