A novel PHKA2 variant in a Chinese boy with glycogen storage diseases type IXa.

Background: Glycogen storage diseases (GSDs) are a group of heterogeneous inherited metabolic disorders with an incidence of 4%-5%. There are 19 types of GSDs, making diagnosis one of the greatest challenges. Methods: The proband and his parents were referred to our hospital for genetic diagnosis. Ultrasound screening suggested hepatomegaly. A novel insertion variant NM_000292 c.1155_1156insT (p. 386N>*) in PHKA2 gene was identified using trio whole exome sequencing (Trio-WES), which resulted in the codon of amino acid 386 from asparagine to termination (p. 386N>*). The 3D mutant protein structure was predicted using AlphaFold, and the results showed that the truncated PHKA2 protein contained 385 of the 1,235 amino acids of the mature protein. Conclusion: We describe a previously unreported case of a GSDs IXa type Chinese boy caused by a novel PHKA2 variant. This clinical case contributes to the understanding of the characteristics of GSDs type IXa and expands the variants spectrum of genes related to GSDs type IXa. Our findings demonstrated the significance of genetic testing in the diagnosis of GSDs.

Evaluation of laboratory critical serum potassium values and their association with clinical symptoms in Chinese Han patients.

OBJECTIVES: A retrospective, observational study to evaluate the association between critical potassium values and clinical symptoms, and to define critical potassium limits in hospital inpatients of Chinese Han ethnicity. METHODS: Adult patients (aged ≥ 18 years) of Chinese Han ethnicity admitted to the Beilun People's Hospital of Ningbo, Zhejiang University, China, were sequentially enrolled. Inpatient data recorded on admission (or at first time during hospital stay for serum potassium values) between 1 January 2011 and 31 December 2012 were used to calculate the percentage of patients with relevant clinical symptoms, the percentage of critical patients (presence of neurological symptoms and deterioration of at least two physiological systems), and the hospital prevalence of clinical symptoms. Correlations between critical serum potassium values and clinical symptoms were determined. RESULTS: Out of 3 665 included patients, 1 514 patients with a critical serum potassium value (as determined in the present study) were mainly treated in the intensive care unit or the haematology department (low serum potassium, ≤ 2.9 mmol/l), and Renal and Hepatitis departments (high serum potassium, ≥ 6.0 mmol/l). High critical serum potassium values (≥ 6.0 mmol/l) were significantly correlated with clinical symptoms (such as neurological symptoms, loss of appetite, oliguria and hypotension). Low critical serum potassium values (≤ 2.9 mmol/l) were significantly correlated with clinical symptoms (such as neurological symptoms, loss of appetite and dyspnoea). CONCLUSIONS: Based on the present findings, the lower and upper critical potassium limits were defined as 2.9 mmol/l and 6.0 mmol/l, respectively.