Bailey-Bloch Congenital Myopathy in Brazilian Patients: A Very Rare Myopathy with Malignant Hyperthermia Susceptibility

Background: Congenital myopathy-13 (CMYP13), also known as Bailey-Bloch congenital myopathy and Native American (NAM), is a condition caused by biallelic missense pathogenic variants in STAC3, which encodes an important protein necessary for the excitation-relaxation coupling machinery muscle. Patients with STAC3 often present weakness arthrogryposis, cleft palate, ptosis, myopathic facies, short stature, kyphoscoliosis, susceptibility to malignant hyperthermia provoked anesthesia. We two unrelated cases of descendants non-consanguineous parents, were investigated delayed psychomotor development generalized weakness. To best our knowledge, these are first descriptions CMYP13 Brazil. In both patients, we found previously described variant p.Trp284Ser homozygosity. Conclusion: seek highlight need screening patients expressing typical phenotype disease even absence Lumbee ancestry, raise awareness possible complications like myopathy.