Diagnosis and treatment of renal glucosuria / 中华实用儿科临床杂志

Renal glycosuria (RG) is an inherited disorder due to defective reabsorption of glucose by the proximal renal tubular.It is attributed to the mutations in the SCL5A2 gene,encoding the sodium-glucose transporter 2 (SGLT2).A defect of SGLT2 is responsible for impaired reabsorption of the filtered glucose in the proximal renal tubular,termed S1,which leads to glycosuria.RG is characterized by normal fasting serum glucose concentration and persistent isolated glucosuria,identification of glucose as the urinary sugar.The inherited pattern of RG is co-dominant inheritance trait with incomplete penetrance.The diagnostic criteria of glycosurias are as follows:a constant and relatively stable urinary glycosurias (10-100 g/d),identification of glucose as the urinary sugar,normal concentration of fasting plasma glucose and normal oral glucose tolerance test,evidence that individuals have normal carbohydrates intake,storage and metabolism.RG does not require special treatment generally,but the advice concerns diet with increasing the intake of carbohydrates.Physical activity should be moderate and professional,and excesive muscle and exercise should be not advisable.

The clinical manifestation and gene mutation of primary renal glucosuria in a child / 临床儿科杂志

Objective To explore the clinical manifestation and gene mutation of primary renal glucosuria (PRG). Methods The clinical data and gene detection results of a child with PRG were analyzed. Results A girl aged 2 years and 10 mouths had glucose ++++ by urine dipstick analysis and 22.4 g of the 24 h urine glucose. Her father was urine glucose positive. Genome DNA was extracted from peripheral blood of the girl and her parents, SLC5A2 gene were amplified by PCR for sequencing, including exons and splicing areas. The results showed a homozygous point mutation (c.127-16C>A) in girl, and both of her patents had the same heterozygous mutation. This mutation had been classified to pathogenic mutations by ClinVar data base. Conclusions The diagnosis of PRG is confirmed in this child and SLC5A2 gene mutation is the cause.

The Na+/glucose cotransporters: from genes to therapy

Glucose enters eukaryotic cells via two types of membrane-associated carrier proteins, the Na+/glucose cotransporters (SGLT) and the facilitative glucose transporters (GLUT). The SGLT family consists of six members. Among them, the SGLT1 and SGLT2 proteins, encoded by the solute carrier genes SLC5A1 and SLC5A2, respectively, are believed to be the most important ones and have been extensively explored in studies focusing on glucose fluxes under both physiological and pathological conditions. This review considers the regulation of the expression of the SGLT promoted by protein kinases and transcription factors, as well as the alterations determined by diets of different compositions and by pathologies such as diabetes. It also considers congenital defects of sugar metabolism caused by aberrant expression of the SGLT1 in glucose-galactose malabsorption and the SGLT2 in familial renal glycosuria. Finally, it covers some pharmacological compounds that are being currently studied focusing on the interest of controlling glycemia by antagonizing SGLT in renal and intestinal tissues.