Distal renal tubular acidosis in Filipino children, caused by mutations of the anion-exchanger SLC4A1 (AE1, Band 3) gene.

AIM: To describe the clinical features and genetic basis of distal renal tubular acidosis (dRTA) in Filipino children. METHODS: Clinical description and gene analysis of affected members of 7 families. RESULTS: In all affected children, the disease was associated with mutations of the SLC4A1 gene that codes for the bicarbonate/chloride anion-exchanger 1 (AE1, band 3) protein situated in the red cell membrane and the alpha-intercalated (proton-secreting) cell of the renal collecting duct. In 2 families, affected children were homozygous for a substitution of aspartic acid for glycine in residue 701 of the AE1 protein (G701D); in the other 5 families, affected children were compound heterozygotes of this mutation with the AE1 mutation (Delta400-408) that causes Southeast Asian ovalocytosis (SAO). All affected children had morphological red cell changes that closely resembled SAO, including the children who were homozygous for G701D and did not have the SAO mutation. Homozygous G701D thus produces morphological red cell changes that are not readily distinguishable from SAO. The parents of all 7 families were originally domiciled in the islands of the Visayas group in the central part of the Philippine archipelago. CONCLUSION: Recessive renal tubular acidosis in Filipinos is usually caused by SLC4A1 mutations, commonly G701D.

Bedside diagnosis of outpatient childhood urinary tract infection using three-media dipslide culture test.

To determine the accuracy of a three-media dipslide test, the Uricult Trio, for the diagnosis of childhood urinary tract infections (UTIs), we collected urine specimens from children at the outpatient department. Two hundred consecutive patients presenting with symptoms of UTI were examined. Randomly voided, midstream, clean-catch and catheterized samples were used. Each was tested by routine laboratory culture and the dipslide test. The subjects' ages ranged from 4 months to 7 years, with a median age of 5 years. There were 112 (56%) boys and 86 (43%) girls. Of the subjects, 98 (49%) showed urine culture results indicating significant bacteriuria. There was complete agreement in 70 cases (35%). The sensitivity and specificity of the dipslide were 68% and 82%, respectively. The positive and negative predictive values were 81% and 71%, respectively. The likelihood ratio for a positive test was 3.7, while for a negative test it was 0.39. The specificity, using Escherichia coli special agar, increased to 85% and the negative predictive value to 93%. The Uricult Trio dipslide method was technically simple and could be applied in the outpatient setting. Further studies are required, however, before it can be recommended as a routine diagnostic tool.