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

PURPOSE: Myotonic dystrophy, also known as dystrophia myotonica (DM), is an autosomal dominant disorder with 2 genetically distinct forms. DM type 1 (DM1) is the more common form and is caused by abnormal expansion of cytosine/thymine/guanine (CTG) repeats in the DM protein kinase (DMPK) gene. Our study aimed to determine whether the age of onset is correlated with CTG repeat length in a population of pediatric patients with DM1. METHODS: We retrospectively identified 30 pediatric patients with DM1 that underwent DMPK testing, of which the clinical data of 17 was sufficient. The cohort was divided into 2 subgroups based on the clinical phenotype (congenital-onset vs. late-onset) and number of CTG repeats ( < 1,000 vs. ≥1,000). RESULTS: We found no significant difference between the age of onset and CTG repeat length in our pediatric patient population. Based on clinical subgrouping, we found that the congenital-onset subgroup was statistically different with respect to several variables, including prematurity, rate of admission to neonatal intensive care unit, need for respiratory support at birth, hypotonia, dysphagia, ventilator dependence, and functional status on last visit, compared to the late-onset subgroup. Based on genetic subgrouping, we found a single variable (poor feeding in neonate) that was significantly different in the large CTG subgroup than that in the small CTG subgroup. CONCLUSION: Clinical variables exhibiting statistically significant differences between the subgroups should be focused on prognosis and designing tailored management approaches for the patients; our findings will contribute to achieve this important goal for treating patients with DM1.
Age of Onset ; Cohort Studies ; Deglutition Disorders ; Genetic Association Studies ; Genotype ; Humans ; Infant, Newborn ; Intensive Care, Neonatal ; Muscle Hypotonia ; Myotonic Dystrophy ; Myotonin-Protein Kinase ; Parturition ; Phenotype ; Prognosis ; Retrospective Studies ; Ventilators, Mechanical

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

The current body of literature contains 5 reports of myotonic dystrophy (DM) with parkinsonism: 4 reports of DM type 2 and 1 report of clinically suspected DM type 1. To date, there have been no genetically proven cases of DM type 1 with parkinsonism. Here, we report the first case of genetically proven DM type 1 and parkinsonism that developed ahead of muscle symptoms with bilateral putaminal, presynaptic dopaminergic deficits on imaging. A 54-year-old female patient presented with bradykinesia, axial and bilateral limb rigidity, stooped posture, and hypomimia, which did not respond to levodopa. At age 56, she developed neck flexion weakness. Examination showed bilateral facial weakness, percussion and grip myotonia, and electromyography confirmed myotonic discharges. A genetic study of DM type 1 showed a DMPK mutation. At age 58, gait freezing, postural instability, and frequent falling developed and did not respond to increasing doses of levodopa. At age 59, the patient died from asphyxia.
Accidental Falls ; Asphyxia ; Electromyography ; Extremities ; Female ; Freezing ; Gait ; Hand Strength ; Humans ; Hypokinesia ; Levodopa ; Middle Aged ; Myotonia ; Myotonic Dystrophy ; Neck ; Parkinsonian Disorders ; Percussion ; Posture

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

PURPOSE: Floppy infants or congenital hypotonia indicates decreased muscle tone in infants secondary to abnormalities of the central or the peripheral nervous system, or both. Previous literature classified its causes as those attributable to a central vs. peripheral origin; however, recent studies have introduced a newer classification describing a combined origin. We invenstigated floppy infants by applying the new etiological classification and reviewed the most common etiologies based on the age of presentation. We additionally reviewed the clinical characteristics, diagnoses, and the developmental outcomes in these infants. METHODS: We retrospectively reviewed the electronic medical charts and recruited 116 infants diagnosed with floppy infant syndrome between January 2005 and December 2016 at Severance Children's Hospital. Among these infants, 66 with a confirmed diagnosis were reviewed for the etiological classification. Information regarding developmental outcomes was obtained via phone interviews with the infants' families. RESULTS: Based on the new etiological classification, among 69 infants with a confirmed diagnosis, in 40 (34.5%) this syndrome was of central origin, in 19 (16.4%) of peripheral origin, and in 10 (8.6%) of combined origin. Prader-Willi syndrome, myotonic dystrophy, and spinal muscular atrophy were the most common disorders observed and combined hypotonia showed the poorest developmental outcome. CONCLUSION: The study states the importance of proper evaluation of etiological diagnosis and optimal intervention for developmental prognosis. The introduction of a new etiological group of combined hypotonia especially emphasizes regular monitoring and timely rehabilitative intervention in patients for the better quality of life in them as well as their caregivers.
Caregivers ; Classification* ; Diagnosis ; Humans ; Infant* ; Muscle Hypotonia ; Muscular Atrophy, Spinal ; Myotonic Dystrophy ; Peripheral Nervous System ; Prader-Willi Syndrome ; Prognosis ; Quality of Life ; Retrospective Studies

Myotonic dystrophy, a multi-systemic disease with cardiac involvement, is the most common inherited neuromuscular disease. Here, we report the results of radiofrequency catheter ablation of persistent atrial fibrillation in a patient with myotonic dystrophy and achalasia-like esophageal dilatation.
Atrial Fibrillation* ; Catheter Ablation* ; Dilatation* ; Humans ; Myotonic Dystrophy* ; Neuromuscular Diseases

PURPOSE: Myotonic dystrophy type 1 (DM1) is characterized by progressive muscular weakness with symptoms caused by involvement of the brain. The aim of this study was to delineate global changes in cortical thickness and white matter integrity in patients with DM1, compared to age-matched healthy controls, and in brain areas highly correlated with CTG repeat size. MATERIALS AND METHODS: Cortical thickness and white matter integrity were compared in nine adult DM1 patients and age matched healthy controls using T1-weighted and diffusion tensor imaging. The patients' intelligence quotient (IQ) and CTG repeat size were measured in each individual. RESULTS: Cortical thickness was significantly reduced in the frontal, temporal, and occipital cortices, while tract-based spatial statistics showed decreased diffusion metrics in widespread areas, including the bilateral orbitofrontal, anterior frontal, insular, external capsule, and occipital cortices in DM1 patients, compared to controls. Additionally, thickness was negatively correlated with the number of CTG repeats in those areas. White matter integrity was negatively correlated with CTG repeats in the left entorhinal, anterior corona radiata, orbitofrontal, and lateral occipital areas. No statistically significant correlation was found between IQ scores and the size of CTG repeats. CONCLUSION: Our results suggest that DM1 is associated with wide distributions of network changes in both gray and white matter. Some of areas related to cognition showed significant correlations with CTG repeats.
Adult ; Brain ; Cognition ; Diffusion ; Diffusion Tensor Imaging ; External Capsule ; Humans ; Intelligence ; Muscle Weakness ; Myotonia ; Myotonic Dystrophy* ; Occipital Lobe ; White Matter*

No abstract available.
Cesarean Section* ; Female ; Myotonic Dystrophy* ; Pregnancy

OBJECTIVE: Although the conventional prevalence of myotonic dystrophy is 1:8,000, the prevalence in Korean population was recently reported as 1:1,245. With higher domestic result than expected, we aimed to investigate the clinical characteristics of pregnancies complicated by congenital myotonic dystrophy in our institution. METHODS: We have reviewed 11 paired cases of neonates diagnosed with congenital myotonic dystrophy and their mothers between July 2004 and May 2014, with clinical features including maternal history of infertility, prenatal ultrasonographic findings, and neonatal outcomes. Cytosine-thymine-guanine (CTG) repeat expansion in the myotonic dystrophy protein kinase gene of both neonates and their mothers was also examined. RESULTS: None of mother was aware of their myotonic dystrophy traits before pregnancy. History of infertility followed by assisted reproductive technology accounted for 57.1% (4/7). Distinctive prenatal ultrasonographic finding was severe idiopathic polyhydramnios (66.7%, 4/6) with median amniotic fluid index of 43 (range, 37 to 66). In 37.5% (3/8) cases, decreased fetal movement was evident during prenatal ultrasound examination. For neonatal outcomes, more than half (6/11) were complicated with preterm birth and the proportion of 1-minute Apgar score <4 and 5-minute Apgar score <7 was 44.4% (4/9) and 66.7% (6/9), respectively. Most of neonates were admitted to the neonatal intensive care unit (9/10) because of hypotonia with respiratory problems and there was one infant death. Median number of cytosine-thymine-guanine repeats in mothers and neonates was 400 (range, 166 to 1,000) and 1,300 (range, 700 to 2,000), respectively. CONCLUSION: Our data suggest that severe idiopathic polyhydramnios with decreased fetal movement in pregnant women, especially with a history of infertility, requires differential diagnosis of congenital myotonic dystrophy.
Amniotic Fluid ; Apgar Score ; Diagnosis, Differential ; Female ; Fetal Movement ; Humans ; Infant Death ; Infant, Newborn ; Infertility ; Intensive Care, Neonatal ; Mothers ; Muscle Hypotonia ; Myotonic Dystrophy* ; Myotonin-Protein Kinase ; Polyhydramnios ; Pregnancy* ; Pregnant Women ; Premature Birth ; Prenatal Diagnosis ; Prevalence ; Reproductive Techniques, Assisted ; Ultrasonography