Clinical features of pediatric renal glucosuria cases due to SLC5A2 gene variants.

BACKGROUND: Familial renal glycosuria (FRG) is a rare renal tubular disorder characterized by a variable loss of glucose in the urine despite normal blood glucose levels, which is seen in a condition in which other tubular functions are preserved. In this study, the molecular and clinical characteristics of pediatric FRG cases due to SLC5A2 gene variants were defined.

METHOD: Demographic features, diagnostic tests, and molecular analyses of patients with a diagnosis of FRG cases due to SLC5A2 gene variants were retrospectively analyzed between 2016-2019.

RESULTS: The data of 16 patients who were clinically and genetically diagnosed with FRG in a four-year period were analyzed. Seven (44%) of the cases were female and nine (56%) were male. The median age at diagnosis was six years old (two months old to seventeen years old). The neuromotor development was found to be appropriate for the age in each case. Systemic blood pressures were evaluated as normal. A homozygous pathogenic variant in the SLC5A2 gene was detected in 14 patients in the genetic examination. A heterozygous variant was detected in one patient. In the other patient, two different heterozygous pathological variants were found in the SLC5A2 gene.

CONCLUSION: It was revealed that growth and development were normal in children with glucosuria due to variations in the SCL5A2 gene, also, renal function tests and urinary amino acid excretion were within normal values. In our case series, the most common genetic variation in the SCL5A2 gene was the A219T (c.655G> A) variant.