A case of simultaneously identified glycogen storage disease and mucopolysaccharidosis / 소아과

Glycogen storage disease (GSD) and mucopolysaccharidosis (MPS) are both independently inherited disorders. GSD is a member of a group of genetic disorders involving enzymes responsible for the synthesis and degradation of glycogen. GSD leads to abnormal tissue concentrations of glycogen, primarily in the liver, muscle, or both. MPS is a member of a group of inherited lysosomal storage diseases, which result from a deficiency in specific enzymatic activities and the accumulation of partially degraded acid mucopolysaccharides. A case of a 16-month-old boy who presented with hepatomegaly is reported. The liver was four finger-breadth-palpable. A laboratory study showed slightly increased serum AST and ALT levels. The liver biopsy showed microscopic features compatible with GSD. The liver glycogen content was 9.3% which was increased in comparison with the reference limit, but the glucose-6-phosphatase activity was within the normal limit. These findings suggested GSD other than type I. Bony abnormalities on skeletal radiographs, including an anterior beak and hook-shaped vertebrae, were seen. The mucopolysaccharide concentration in the urine was increased and the plasma iduronate sulfatase activity was low, which fulfilled the diagnosis criteria for Hunter syndrome (MPS type II). To the best of the authors' knowledge, this is the first case of GSD and Hunter syndrome being identified at the same time.

A Case of Hereditary Fructose Intolerance

Hereditary fructose intolerance(HFI) is an autosomal recessive disease caused by catalytic deficiency of aldolase B in which affected homozygotes develop hypoglycemia and abdominal symptoms after taking foods containing fructose. Chronic exposure to fructose may lead to progressive hepatic injury, renal injury, growth retardation, and ultimately to liver and kidney failure. Herein, we report a case of HFI with presentation of episodic vomiting, diarrhea, cold sweating, abnormal liver function and failure to thrive after 12 months of her age. She developed an aversion to fruits and sweet-tasting foods. When she was admitted to hospital at the age of 30 months, hepatomegaly, and dysfunction of proximal renal tubule with renal tubular acidosis were noted. We confirmed the diagnosis via enzyme assay on biopsied liver and intestine. A fructose restrictied diet was recommended. The patient has been symptom free with normal liver functions since then.

Reference Values for Cystatin C Serum Concentrations in Children / 대한신장학회잡지

Cystatin C is a non-glycated 13-kilodalton basic protein produced by all nucleated cells. It has received considerable attention over the last few years as a potential replacement for creatinine as a biochemical marker for glomerular filtration rate(GFR). Recently published studies have shown that cystatin C correlates more strongly than creatinine with GFR. The aim of this study was to define a reference interval for cystatin C concentrations in children. Cystatin C was measured by an immunonephelometric assay in sera obtained from 102 children(47 boys, 55 girls, range from 1 year to 15 years) without evidence of kidney disease. The reference interval was calculated non-parametrically using the 2.5 th and 97.5th percentiles. Cystatin C concentration was constant regardless of age and sex, with a reference interval of 0.512-1.104mg/L. In contrast, serum creatinine concentration increased steadily with age until adulthood. Cystatin C offers easier recognition of renal function in childhood because its reference value is constant through all ages beyond 1 year.