1/4. Identification of a novel mutation in the ryanodine receptor gene (RYR1) in a malignant hyperthermia Italian family.malignant hyperthermia (MH) is an inherited autosomal dominant pharmacogenetic disorder and is one of the main causes of death subsequent to anaesthesia. Around 50% of affected families are linked to the ryanodine receptor (RYR1) gene. To date, 19 mutations have been identified in the coding region of this gene and appear to be associated with the MH-susceptible phenotype. Here we report the identification by two independent methods of a novel mutation associated with the MH-susceptible phenotype in the RYR1 gene: the 6488G-->C transversion, resulting in the replacement of the Arg2163 with a proline residue.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
2/4. Familial achalasia in sudan.An 8-month old Sudanese male child with a history of recurrent vomiting since the age of 4 months was referred for upper gastrointestinal edoscopy, which showed a dilated oesophagus and a tight lower esophageal sphincter. The child was diagnosed as having achalasia, which was successfully treated with pneumatic dilatation under General anaesthesia.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
3/4. ryanodine receptor gene point mutation and malignant hyperthermia susceptibility.malignant hyperthermia (MH) is a rare clinical syndrome, triggered in susceptible subjects by a variety of anaesthetic agents and muscle relaxants, and is the commonest cause of death due to general anaesthesia. Previous studies have reported that inherited mutations in the ryanodine receptor (RYR1) gene co-segregated, in some families, with MH susceptibility; lack of linkage between MH and the RYR1 gene in some other families indicates a heterogenous genetic basis for the syndrome. The in vitro contracture test (IVCT) on muscle biopsy specimens is considered to be the most reliable test for establishing the diagnosis of MH. With the identification of RYR1 point mutations this might in turn result in non-invasive methods for the presymptomatic diagnosis of MH. In the present study we investigated four families suspected to be at risk of MH susceptibility; in all subjects histopathological examination and IVCT were performed on muscle biopsy specimens. We undertook a mutation analysis of RYR1 gene testing for the presence of five point mutations; in one pedigree a C1840-->T point mutation was detected, strictly segregating with in vitro MH susceptibility.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
4/4. malignant hyperthermia susceptibility, an autosomal dominant disorder?A large series of Swedish nuclear families, in which malignant hyperthermia (MH) reactions had occurred during anaesthesia, have been examined with respect to malignant hyperthermia susceptibility. in vitro contracture tests (IVCT) of muscle strips were conducted to diagnose MH status. Included in this series were some families where only one of the parents was tested by IVCT, while in 79 of the families both parents were tested by IVCT. Six known mutations in the gene encoding the calcium release channel of sarcoplasmic reticulum in skeletal muscle (the RYR1 gene), believed to cause MHS in man, were searched for in 41 nuclear families. The present paper focuses on findings in eight families, where both parents were malignant hyperthemia negative (MHN), while at least one child was either malignant hyperthermia susceptible (MHS) or malignant hyperthermia equivocal (MHE). There was no suggestion of non-paternity. The RYR1 mutations investigated were Arg163Cys, Gly341Arg, Ile403Met, Arg614Cys, Gly2433Arg and Arg2434His. No family had any of the six RYR1 mutations searched for.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |