Differences in Features and Course of Mucosal Type Eosinophilic Gastroenteritis between Korean Infants and Children.

Eosinophilic gastroenteritis (EGE) is a disorder characterized by eosinophilic infiltration of the bowel wall and various gastrointestinal (GI) manifestations. This study aimed to evaluate the characteristics of EGE in infants and children. A total of 22 patients were diagnosed with histologic EGE (hEGE) or possible EGE (pEGE). Serum specific IgE levels, peripheral eosinophil counts, and endoscopic biopsies were carried out. In the hEGE group (n = 13), initial symptoms included hematemesis, abdominal pain, and vomiting. Three of the subjects had normal endoscopic findings. Eight patients were categorized into the infant group and 5 into the child group. All patients in the infant group showed clinical improvement after switching from cow's milk feeding to special formula or breast feeding. The infant group showed a higher eosinophil count in the gastric mucosal biopsy than the child group. In the pEGE group (n = 9) initial symptoms included hematemesis, abdominal pain, and vomiting. Seven patients in this group showed a good response to treatment with restriction of the suspected foods and/or the administration of ketotifen. Both hEGE and pEGE groups showed clinical improvement after restriction of suspected foods in the majority of cases and also showed a similar clinical course. EGE should be considered in the differential diagnosis of patients with chronic abdominal pain, vomiting, and hematemesis of unknown cause. The infant group may have a better prognosis than the child group if treated properly.

A cell function study on calcium regulation of a novel calcium-sensing receptor mutation (p.Tyr825Phe).

PURPOSE: Autosomal dominant hypocalcemia with hypercalciuria is a genetic disease characterized by hypoparathyroidism with hypercalciuria. We discovered a novel variant (p.Tyr825Phe[Y825F]) of the CASR gene in a neonate with congenital hypoparathyroidism and hypercalciuria and conducted a cell function study to determine whether the CASR-Y825F variant was pathogenic. METHODS: To perform a functional study on CaSR-Y825F, we constructed expression vectors expressing wild-type (WT) CASR and CASR-Y825F. After transfection of each expression vector into HEK293 cells, we examined alterations in intracellular signaling. Mitogen-activated protein kinase (MAPK) signaling activity of HEK293 cells expressing CASR-WT or CASR-Y825F was determined. Changes in intracellular calcium ions ([Ca2+]i) by extracellular calcium ion ([Ca2+]e) stimulation were quantitatively compared and analyzed. RESULTS: Cells expressing CASR-Y825F showed elevated of MAPK signaling (phospho-ERK [pERK], phospho-JNK [pJNK], phospho-p38 [pp38]) and increased [Ca2+]i levels at low [Ca2+]e stimulation compared with cells expressing CASR-WT. Additionally, [Ca2+]i levels in HEK293 cells expression CASR-WT and CASR-Y825F were determined at 340 nm/380 nm wavelength ratios using Fura-2 AM. At [Ca2+]e concentrations of 2.5 mM and 3 mM, the ratios of CASR-Y825F cells were higher (2.6 and 3.5, respectively) than those of CASR-WT cells (1.04 and 1.40, respectively). CONCLUSION: This cell function study proved that the CASR-Y825F expressed in HEK293 cells elevated MAPK signaling (pERK, pJNK, pp38) and increased [Ca2+]i to induce hypocalcemia.

De novo a novel variant of CaSR gene in a neonate with congenital hypoparathyroidism.

Autosomal-dominant hypocalcemia with hypercalciuria (ADHH) is a genetic disease characterized by hypoparathyroidism with hypercalciuria. Most patients with ADHH have calcium-sensing receptor (CaSR) gene mutations. The CaSR gene controls parathyroid secretions, and mutations in this gene can be detected via changes in serum calcium level. The activating mutation of the CaSR gene results in familial or sporadic ADHH. Most activating mutations of the CaSR gene are reportedly de novo missense mutations. This is the first case report of a novel activating variant of the CaSR gene in a neonate with congenital hypoparathyroidism with hypomagnesemia and hypercalciuria. We also report the 3-month follow-up management of the patient.