Here we report the molecular characterization of Out-cold (Ocd) mutants of Drosophila melanogaster, which produce a dominant, X-linked, cold-sensitive paralytic phenotype. From its initial 1.5-Mb cytological location within 13F1-16A2, P-element and SNP mapping reduced the Ocd critical region to <100 kb and to six candidate genes: hangover, CG9947, CG4420, eIF2a, Rbp2, and paralytic (para). Comp...

Laryngospasm is a rare but potentially life-threatening occurrence in infants and usually has infective, allergic, metabolic, or anatomic causes. Underlying genetic conditions are rarely considered. Mutations in SCN4A encoding the voltage-gated sodium channel NaV1.4 have been implicated in a wide spectrum of neuromuscular disorders with variable onset, ranging from a rare form of congenital mya...

To test the hypothesis of a general defect in the ion transport systems in the cell membranes of patients with paramyotonia congenita, we measured the ouabain-inhibitable and the furosemide-inhibitable K+ influxes in erythrocytes from two patients. In the temperature range examined (15-40 degrees C), the ouabain-inhibitable flux did not differ significantly from control. Also the furosemide-inh...

By the introduction of technological advancement in methods of structural analysis, electronics, and recombinant DNA techniques, research in physiology has become molecular. Additionally, focus of interest has been moving away from classical physiology to become increasingly centered on mechanisms of disease. A wonderful example for this development, as evident by this review, is the field of i...

OBJECTIVES To define a new type of dominant myotonic muscle disorder and to identify the gene lesion. DESIGN Case series, clinical examination and electromyography, measurements of grip force and relaxation time, and DNA analysis to probe for mutation in the gene for the skeletal muscle sodium channel. SETTING Outpatient clinic and home. PATIENTS Three families studied; all together, 17 a...