The ryanodine receptor type 1 gene variants in African American men with exertional rhabdomyolysis and malignant hyperthermia susceptibility.
It has been suggested that exertional rhabdomyolysis (ER) and malignant hyperthermia (MH) are related syndromes. We hypothesize that patients with unexplained ER harbor mutations in the ryanodine receptor gene type 1 (RYR1), a primary gene implicated in MH, and therefore ER patients are at increased risk for MH. Although there are reported cases of MH in individuals of African descent, there are no data available on molecular characterization of these patients. We analyzed RYR1 in six, unrelated African American men with unexplained ER, who were subsequently diagnosed as MH susceptible (MHS) by the Caffeine Halothane Contracture Test. Three novel and two variants, previously reported in Caucasian MHS subjects, were found in five studied patients. The novel variants were highly conserved amino acids and were absent among 230 control subjects of various ethnic backgrounds. These results emphasize the importance of performing muscle contracture testing and RYR1 mutation screening in patients with unexplained ER. The MHS-associated variant Ala1352Gly was identified as a polymorphism predominant in individuals of African descent. Our data underscore the need for investigating RYR1 across different ethnic groups and will contribute to interpretation of genetic screening results of individuals at risk for MH.
Sambuughin
N
N
Department of Anesthesiology, Uniformed Services University of Health Sciences, Bethesda, MD 20814, USA. sambuughin@usuhs.mil
Capacchione
J
J
Blokhin
A
A
Bayarsaikhan
M
M
Bina
S
S
Muldoon
S
S
D000328:Adult; D001741:Black or African American / Q000235:genetics*; D016022:Case-Control Studies; D004252:DNA Mutational Analysis; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D006801:Humans; D008297:Male; D008305:Malignant Hyperthermia / Q000150:complications* / Q000235:genetics / Q000503:physiopathology; D009119:Muscle Contraction / Q000502:physiology; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D005082:Physical Exertion; D012206:Rhabdomyolysis / Q000150:complications* / Q000235:genetics* / Q000503:physiopathology; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics*; D055815:Young Adult
D019837:Ryanodine Receptor Calcium Release Channel