Glycogen Storage Disease Type IIIa Presenting with Hyperglycemia: A Novel Mutation

The disorder usually involves both liver and muscle and is termed glycogen storage diseases type IIIa. However, in about 15% of patients, the disease appears to involve only the liver and is classified as type IIIb. Hypoglycemia, hepatomegaly and progressive myopathy are prominent clinical findings. The presence of a wide variety of mutations in the AGL gene causing disease has been described in the literature.2-4 This new mutation we found in the AGL gene has not been yet published. In this case, we aimed to present our case of a 44-year-old Turkish male diagnosed as glycogen storage disease type IIIa, accompanied by this new mutation with hyperglycemia associated with type 2 diabetes mellitus without hypoglycemia. CASE REPORT A 44-year-old male patient was admitted to our clinic with complaints of inability to walk, dry mouth, polydipsia and polyuria. There is no known family history of diabetes mellitus and glycogen storage disease. Physical exam showed hepatomegaly, muscle weakness and atrophy of the distal extremities. The patient’s height was 165 cm and weight 50 kg.When he was 20 years old, he was diagnosed with glycogen storage disease (GSD) by muscle biopsy due to myopathy but at that time the type of the disease was not determined.The patient first noticed muscle weakness of the distal extremities at the age of 20. The symptoms gradually increased, and he could no longer walk without walking stick. In blood tests, glucose: 262 mg/dl, ALT: 74 U/L, AST: 50 U/L creatinine kinase (CK): 898 U/L HBA1c: 10.3% was detected. The laboratory results of the patient are shown in Table 1. Turkiye Klinikleri J Case Rep. 2020;28(3):173-6