Abnormal calcium transport may be implicated in the membrane defect in myotonic dystrophy. A single blind crossover trial of placebo (t.i.d.), nifedipine 10 mg (t.i.d.) and nifedipine 20 mg (t.i.d.), was performed in 10 patients with myotonic dystrophy. The severity of myotonia was assessed by measuring finger extension time after maximum voluntary finger flexion. A significant improvement in m...

The extraocular muscles of the C57BL/6Jdy-2j myotonic mouse were studied by phase and electron microscopy. The most susceptible ocular muscle was the levator palpebrae; the other muscles manifested scattered abnormalities to varying degrees. Central nucleation and fiber splitting were prominent. Junctional abnormalities consisted of a reduction in post-junctional folding, excessive numbers of a...

A 32-year-old man with myotonic dystrophy underwent a thoracotomy for removal of a mediastinal thymoma. Pre-operative examination revealed features of myotonic dystrophy, the only other abnormality was mild restrictive pulmonary disease. Anaesthesia was induced with thiopentone and maintained with enflurane, nitrous oxide, oxygen and curare. Following surgery, the patient was mechanically venti...

Myotonic Dystrophy is an autosomally dominant inherited disease affecting individuals of all ages. It’s prevalence among Caucasians is estimated at 35 per 100,000 individuals in the population. (1) The age of onset allows for specific classification of the disease into one of four categories: congenital, which appears at birth; juvenile, appearing up through teenage years; adult, symptoms start...

The results of DNA analysis for the specific mutation of myotonic dystrophy are reported in eight pregnancies (two studied retrospectively) in six families. Four results were normal; in the other four, large DNA expansions were found, comparable to the range seen in severely affected children with congenital onset of the disorder. The results agreed with those obtained by linked DNA markers in ...

Variations in DNA sequence generate polymorphisms which can be followed through families. A cloned gene specific probe for human complement 3 (C3) was hybridised to DNA samples digested with restriction endonucleases. The C3 probe detects several restriction fragment length polymorphisms (RFLPs) that occur frequently in the general population. These DNA alleles can be readily used in linkage an...

Myotonic dystrophy (MD) is characterized by myotonia and muscular dystrophy and cardiac involvement with tachy-arrhythmia is rarely encountered. We report a case of MD complicated with severe left ventricular hypofunction and incessant ventricular tachycardia (VT) with varying heart rates. The morphology of VT suggested that it originated from the right ventricular outflow tract, and electrophy...

We evaluated the frequency of cerebral infarction in 131 patients with Duchenne's muscular dystrophy, myotonic dystrophy, Becker's muscular dystrophy, or Friedreich's ataxia. Electrocardiographic abnormalities were found in 83% of patients with Duchenne's muscular dystrophy, 56% with myotonic dystrophy, 50% with Becker's muscular dystrophy, and 25% with Friedreich's ataxia. Atrial flutter occur...

Myotonic dystrophy (Dystrophia Myotonica, DM) is the most frequently inherited neuromuscular disease of adult life. It is a multisystemic disease with major cardiac involvement. Core features of myotonic dystrophy are myotonia, muscle weakness, cataract, respiratory failure and cardiac conduction abnormalities. Classical DM, first described by Steinert and called Steinert's disease or DM1 (Dyst...

Background & Aims: Nearly 30 hereditary disorders in humans result from an increase in the number of copies of simple repeats in genomic DNA, including fragile X syndrome, myotonic dystrophy, Huntington’s disease, and Friedreich’s ataxia. One the most frequently occurring types of mutation is trinucleotide repeat expansion. The present study was conducted with the aim of investigating the cause...