Clinical and Genetic Spectrum of RYR1-Related Disease

In this study, we examined the genotype-phenotype characteristics of the cases with pathogenic/possibly pathogenic variants in the RYR1 gene that we follow in our clinic.

Data of patients who applied to our clinic and had pathogenic/possibly pathogenic/variant of unknown significance variants in the RYR1 gene were evaluated retrospectively. Patients were examined in terms of demographic, clinical, and individual genetic data, age of symptom-onset, sex, clinical features, clinical types, variants, cardiac involvement, muscle biopsy results, serum creatinine kinase (CK) levels, family history, and consanguinity.

The variants were detected in 19 patients from 18 different families. The most common (n = 5, 38.4%) variant was the c.7880T>G (p.Val2627Gly) heterozygous change. 63.1% of our patients were male (n = 12) and 37.9% were female. Admission complaints included a floppy baby, developmental delay, or hyperCKemia. The most common clinical spectrum was malignant hyperthermia (MH) sensitivity (n = 8, 44.4%). We also identified four novel variants in our cohort.

RYR1 is known to be the gene most associated with MH. It is very important to manage and take precautions against possible comorbidities and anesthesia complications. For this reason, we think that RYR1 analyses should be given priority in the diagnostic algorithm.