GNE myopathy in the Bedouin population of Kuwait: Genetics, prevalence and clinical description.

Introduction: GNE myopathy is a rare recessive myopathy caused by mutations in the GNE gene. It is mainly a distal myopathy with relative sparing of the quadriceps muscle. Methods: Patients with distal myopathies from Kuwait were examined and tested for the Middle Eastern GNE gene founder mutation, p.M743T. Patients were further studied for disease-associated features. Results: GNE myopathy was confirmed in 14 of the 37 patients (37.8%) screened. All cases were caused by the p.M743T mutation. Age of onset and time from disease onset to loss of ambulation were variable. Both wasted and hypertrophied calf muscles were noted. Severely affected quadriceps were present in 1 patient, and ptosis, ophthalmoplegia, and tongue wasting in another. Discussion: The scope of the p.M743T mutation now includes the Arabian Peninsula. Variations in age of onset, disease progression, and distribution in patients harboring the same mutation suggest the role of other genetic- and environment-modifying factors. Muscle Nerve 58: 700-707, 2018