Humans ; Myotonia Congenita/genetics* ; Mutation ; NAV1.4 Voltage-Gated Sodium Channel/genetics*

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

Neuromyelitis optica spectrum disorder (NMOSD) is generally known as selective involvement of central nervous system. However, in recent years, some evidences have been found that NMOSD invades other peripheral organs. Especially, skeletal muscle involvement of NMOSD has been documented scantily and further studies must be required. Here, we describe a patient who first had generalized fatigue, mild weakness, and myalgia with increased level of serum creatine kinase and was finally diagnosed with myopathy associated with NMOSD.
Central Nervous System ; Creatine Kinase ; Fatigue ; Humans ; Muscle, Skeletal ; Muscular Diseases ; Myalgia ; Myotonia ; Myotonic Disorders ; Neuromyelitis Optica

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

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

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

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

No abstract available.
Dyskinesias ; Myotonia Congenita ; Myotonia

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

PURPOSE: We report two cases of strabismus on myotonic dystrophy treated with a surgical procedure. CASE SUMMARY: A 49-year-old female with myotonic dystrophy presented with exotropia above 50 prism diopters and limitation of eye movement at nasal and inferior gaze in both eyes. We performed 9.25 mm lateral rectus recession in her right eye and 8.75 mm lateral rectus recession in her left eye. After surgery, she had 40 prism diopter residual exotropia. A 39-year-old female with myotonic dystrophy type 1 had outward deviation of her left eye. Prism cover-uncover test revealed 40 prism diopter exotropia at near distance and 25 prism diopter exotropia at far distance. We performed 6.0 mm lateral rectus recession and 4.5 mm medial rectus tucking in her left eye. Three months after surgery, the prism cover-uncover test showed 10 prism diopter residual intermittent exotropia at near distance and 6 prism diopter residual exophoria at far distance. CONCLUSIONS: Not only cataract and retinal lesion, but also abnormal ocular movement and strabismus due to weakened extraocular muscles can occur in myotonic dystrophy patients. We recommend examination for functions of extraocular motility to diagnose and to treat for maintaining relatively straight alignment.
Adult ; Cataract ; Exotropia ; Eye Movements ; Female ; Humans ; Middle Aged ; Muscles ; Myotonic Dystrophy* ; Retinaldehyde ; Strabismus*