Learn More
Myotonia congenita (MC) is the commonest genetic skeletal muscle ion channelopathy. It is caused by mutations in CLCN1 on chromosome 7q35, which alter the function of the major skeletal muscle voltage-gated chloride channel. Dominant and recessive forms of the disease exist. We have undertaken a clinical, genetic and molecular expression study based upon a(More)
The non-dystrophic myotonias are an important group of skeletal muscle channelopathies electrophysiologically characterized by altered membrane excitability. Many distinct clinical phenotypes are now recognized and range in severity from severe neonatal myotonia with respiratory compromise through to milder late-onset myotonic muscle stiffness. Specific(More)
Periodic paralyses (PPs) are rare inherited channelopathies that manifest as abnormal, often potassium (K)-sensitive, muscle membrane excitability leading to episodic flaccid paralysis. Hypokalaemic (HypoPP) and hyperkalaemic PP and Andersen-Tawil syndrome are genetically heterogeneous. Over the past decade mutations in genes encoding three ion channels,(More)
Mutations in the gene coding for the catalytic subunit of the mitochondrial DNA (mtDNA) polymerase g (POLG1) have recently been described in patients with diverse clinical presentations, revealing a complex relationship between genotype and phenotype in patients and their families. POLG1 was sequenced in patients from different European diagnostic and(More)
OBJECTIVES To obtain minimum point prevalence rates for the skeletal muscle channelopathies and to evaluate the frequency distribution of mutations associated with these disorders. METHODS Analysis of demographic, clinical, electrophysiologic, and genetic data of all patients assessed at our national specialist channelopathy service. Only patients living(More)
Mutations in the gene coding for the catalytic subunit of the mitochondrial DNA (mtDNA) polymerase gamma (POLG1) have recently been described in patients with diverse clinical presentations, revealing a complex relationship between genotype and phenotype in patients and their families. POLG1 was sequenced in patients from different European diagnostic and(More)
Myotonia congenita is caused by mutations in the voltage-gated chloride channel ClC-1. It is more severe in men than women and often worsens during pregnancy, but the basis for these gender differences is not known. We show here that both testosterone and progesterone rapidly and reversibly inhibit wild-type ClC-1 channels expressed in Xenopus oocytes by(More)
  • N P Davies, P Imbrici, +17 authors M G Hanna
  • 2005
OBJECTIVE To evaluate clinical, genetic, and electrophysiologic features of patients with Andersen-Tawil syndrome (ATS) in the United Kingdom. METHODS Clinical and neurophysiologic evaluation was conducted of 11 families suspected to have ATS. Molecular genetic analysis of each proband was performed by direct DNA sequencing of the entire coding region of(More)
OBJECTIVE To study the clinical and genetic features in a large cohort of UK patients with sodium channel paramyotonia congenita. METHODS We conducted a UK-wide clinical and molecular genetic study of patients presenting with a phenotype suggestive of paramyotonia congenita. RESULTS We identified 42 affected individuals (28 kindreds). All cases met our(More)
The effect of intrastriatal administration of glutaric acid (GTR), a metabolite that accumulates in glutaric acidemia type I (GA-I), on the behavior of adult male rats was investigated. After cannula placing, rats received unilateral intrastriatal injections of GTR buffered to pH 7.4 with NaOH or NaCl. GTR induced rotational behavior toward the(More)