Objective: Glycogen storage disease type IX (GSD-IX) is a rare primary glucose metabolism abnormality caused by phosphorylase kinase deficiency and a series of pathogenic gene mutations. The clinical characteristics, gene analysis, and functional verification of a mutation in a child with hepatomegaly are summarized here to clarify the pathogenic cause of the disease. Methods: The clinical data of a child with GSD-IX was collected. Peripheral blood from the child and his parents was collected for genomic DNA extraction. The patient's gene diagnosis was performed by second-generation sequencing. The suspected mutations were verified by Sanger sequencing and bioinformatics analysis. The suspected splicing mutations were verified in vivo by RT-PCR and first-generation sequencing. Results: Hepatomegaly, transaminitis, and hypertriglyceridemia were present in children. Liver biopsy pathological examination results indicated glycogen storage disease. Gene sequencing revealed that the child had a c.285 + 2_285 + 5delTAGG hemizygous mutation in the PHKA2 gene. Sanger sequencing verification showed that the mother of the child was heterozygous and the father of the child was of the wild type. Software such as HSF3.1 and ESEfinder predicted that the gene mutation affected splicing. RT-PCR of peripheral blood from children and his mother confirmed that the mutation had caused the skipping of exon 3 during the constitutive splicing of the PHKA2 gene. Conclusion: The hemizygous mutation in the PHKA2 gene (c.285 + 2_285 + 5delTAGG) is the pathogenic cause of the patient's disease. The detection of the novel mutation site enriches the mutation spectrum of the PHKA2 gene and serves as a basis for the family's genetic counseling.
Child ; Humans ; Exons ; Glycogen Storage Disease/genetics* ; Hepatomegaly/genetics* ; Mutation ; Phosphorylase Kinase/genetics* ; Male ; Female

OBJECTIVE: To explore the genetic etiology of a patient with glycogen storage diseases. METHODS: Clinical data of child and his parents were collected. The genes associated with glycogen storage diseases were subjected to high-throughput sequencing to screen the variants. Candidate variant was validated by Sanger sequencing. Pathogenicity of the variant was predicted by bioinformatic analysis. RESULTS: High-throughput sequencing results showed that the boy has carried a hemizygous c.749C>T (p.S250L) variant of the PHKA2 gene. Sanger sequencing verified the results and confirmed that it was inherited from his mother. This variant was unreported previously and predicted to be pathogenic by bioinformatic analysis. CONCLUSION The patient was diagnosed with glycogen storage disease type IXa due to a novel c.749C>T (p.S250L) hemizygous variant of the PHKA2 gene. High-throughput sequencing can facilitate timely and accurate differential diagnosis of glycogen storage disease type IXa.
Child ; Family ; Genetic Testing ; Glycogen Storage Disease/pathology* ; High-Throughput Nucleotide Sequencing/methods* ; Humans ; Male ; Mutation ; Phosphorylase Kinase/genetics*

Glycogen storage disease type IX (GSD IX) is caused by a defect in phosphorylase b kinase (PhK) that results from mutations in the PHKA2, PHKB, and PHKG2 genes. Patients usually manifest recurrent ketotic hypoglycemia with growth delay, but some may present simple hepatomegaly. Although GSD IX is one of the most common causes of GSDs, its biochemical and genetic diagnosis has been problematic due to its rarity, phenotypic overlap with other types of GSDs, and genetic heterogeneities. In our report, a 22-month-old boy with GSD IX is described. No other manifestations were evident except for hepatomegaly. His growth and development also have been proceeding normally. Diagnosed was made by histologic examination, an enzyme assay, and genetic testing with known c.3210_3212del (p.Arg1070del) mutation in PHKA2 gene.
Child* ; Diagnosis ; Enzyme Assays ; Genetic Heterogeneity ; Genetic Testing ; Glycogen Storage Disease ; Glycogen* ; Growth and Development ; Hepatomegaly* ; Humans ; Hypoglycemia ; Infant ; Male ; Phosphorylase Kinase

The enzyme activities of creatine kinase(CK), its isoenzyme MB(CK-MB) and of lactate dehydrogenase isoenzyme 1(LD-1) have been used for years in diagnosing patients with chest pain in order to differentiate patients with acute myocardial infarction(AMI) from non-AMI patients. These methods are easy to perform as automated analyses, but they are not specific for cardiac muscle damage. During the early 90's the situation changed. First, creatine kinase MB mass(CK-MB mass) replaced the measurement of CK-MB activity. Subsequently cardiac-specific proteins, troponin T(cTnT) and troponin I(cTnI) appeared and displacing LS-1 analysis. However troponin concentration in blood increase only from four to six hours after onset of chest pain. Therefore a rapid marker such as myoglobin, fatty acid binding protein or glycogen phosphorylase BB could be used in early diagnosis of AMI. On the other hand, CK-MB isoforms alone may also be useful in rapid diagnosis of cardiac muscle damage. Myoglobin, CK-MB mass, cTnT and cTnI are nowadays wisely used in diagnosing patients with acute chest pain. Myoglobin is not cardiac-specific and therefore requires supplementation with some other analysis such as troponins to support the myoglobin value. Troponins are very highly cardiac-specific. Only the sera of some patients with severe renal failure, which requires hemodialysis, have elevated cTnT and/or cTnI without there being any evidence of cardiac damage. The latest studies have shown that elevated troponin levels in sera of hemodialysis patients point to an increased risk of future cardiac events in a similar manner to the elevated troponin values in sera of patiets with unstable angina pectoris. In addition, the bedside tests for cTnT and cTnI alone or together with myoglobin and CK-MB mass can be used instead of quantitative analyses in the diagnosis of patients with chest pain. These rapid tests are easy to perform and they do not require expensive instrumentation. For the diagnosis patients with chest pain, routinely myoglobin and CK-MB mass measurements should be performed whenever they are requested (24 h/day) and cTnT and cTnI on admission to the hospital and then 4-6 and 12 hours later and maintained less than 10% imprecision.
Acute Coronary Syndrome* ; Angina, Unstable ; Carrier Proteins ; Chest Pain ; Creatine ; Creatine Kinase ; Diagnosis ; Early Diagnosis ; Glycogen Phosphorylase ; Hand ; Humans ; L-Lactate Dehydrogenase ; Myocardial Infarction ; Myocardium ; Myoglobin ; Protein Isoforms ; Renal Dialysis ; Renal Insufficiency ; Troponin

Glycogen storage disease type V (GSD-V) is the most common disorder of muscle glycogenosis with characteristic clinical and laboratory findings. A 32-yr-old woman complained of exercise intolerance and myoglobulinuria since early adolescence. She reported several episodes of second-wind phenomenon. Physical examination did not show any neurological abnormality, including fixed muscle weakness or atrophy. Serum creatine kinase level was 1,161 IU/L at rest. The result of the non-ischemic forearm exercise test was compatible with GSD-V. Mutation analysis identified the compound heterozygous mutations of the PYGM, p.D510fs and p.F710del, which has not yet been reported in Korea. The present case recognizes that detail clinical and laboratory analysis is the first step in the diagnosis of GSD-V.
Adult ; Base Sequence ; Creatine Kinase/blood ; Exons ; Female ; Frameshift Mutation ; Gene Deletion ; Genotype ; Glycogen Phosphorylase, Muscle Form/genetics ; Glycogen Storage Disease Type V/*diagnosis/genetics/pathology ; Humans ; Pedigree ; Sequence Analysis, DNA

OBJECTIVETo investigate the changes and the clinical significance of N-terminal pro-brain natriuretic peptide (NT-proBNP) and glycogen phosphorylase isoenzyme BB (GPBB) levels in neonates with asphyxia complicated by myocardial injury.

METHODSSixty-four neonates with asphyxia (39 mild, 25 severe) were enrolled. Of the 64 neonates, 30 had myocardial injury and 34 did not develop myocardial injury. Twenty-five healthy neonates served as a control group. Plasma levels of NT-proBNP and GPBB were measured using ELISA. Myocardial enzymes and cardiac troponin I were stimultaneously measured, and electrocardiography and chest radiographs were obtained.

RESULTSThe plasma levels of NT-proBNP and GPBB in neonates with myocardial injury were significantly higher than those in neonates without myocardial injury and in the control group (P<0.01). The neonates with severe asphyxia had significantly increased plasma NT-proBNP and GPBB concentrations compared to those with mild asphyxia and the control group (P<0.01). Spearman rank correlation analysis showed that plasma NT-proBNP level was positively correlated with plasma GPBB level in neonates with asphyxia. Plasma levels of NT-proBNP and GPBB were also positively correlated with plasma levels of CK-MB, CK and LDH (P<0.01).

CONCLUSIONSBoth NT-proBNP and GPBB can be used as biomarkers of myocardial injury in neonates with asphyxia. The measurement of plasma NT-proBNP and GPBB levels was useful in early identification of myocardial injury and severity evaluation in neonates with asphyxia.

Asphyxia Neonatorum ; blood ; Cardiomyopathies ; blood ; Creatine Kinase, MB Form ; blood ; Enzyme-Linked Immunosorbent Assay ; Female ; Glycogen Phosphorylase ; blood ; Humans ; Infant, Newborn ; Male ; Natriuretic Peptide, Brain ; blood ; Peptide Fragments ; blood