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Author(s): Anil Vasudevan [sup.1] , Kishore Phadke [sup.2 ] , Hui-Kim Yap [sup.3] [sup.4] Author Affiliations: (1) 0000 0004 1770 8558, grid.416432.6, Department of Pediatric Nephrology, St. John's Medical College [...]

Background Vesicoureteral reflux (VUR) has a prevalence of 30-40% post-febrile urinary tract infection (UTI). If not detected early and treated, renal scarring, hypertension, and renal failure may occur. Micturating cystourethrography (MCU) is an invasive procedure associated with radiation exposure. Hence, this study aimed at evaluating the utility of ureteric jet Doppler waveform (UJDW) as a screening tool in detecting VUR, and at assessing the feasibility of performing it in children aged 2-4 years. Methods Any child 2-18 years old who needed an MCU was included. Exclusion criteria were active UTI, indwelling catheter, and inability to drink the required amount of fluid. The UJDW was performed prior to the MCU. Results One hundred eighty-two ureteric units were analyzed. Sensitivity and specificity of UJDW in detecting VUR was 80.3 and 87.9%. Twenty-three children (45 ureteric units), aged 2-4 years were compared with 73 children (137 ureteric units), aged 5-18 years. Sensitivity and specificity of UJDW in detecting VUR in 2-4 years was 77.3 and 91.3%, respectively; while in children >5 years, it was 81.8 and 87.1%, respectively. Conclusions UJDW has a uniformly high specificity regardless of age or etiological groups, making it a good tool for follow-up. UJDW is a feasible technique, even in children aged 2-4 years. Keywords Children * Micturating cystourethrography * Ureteric jet Doppler waveform * Vesicoureteral reflux, Introduction Vesicoureteral reflux (VUR) is a common risk factor for urinary tract infections (UTI) in children. It is seen in 30-50% of all children and 40-50% of infants presenting with [...]

Abstract Background Single nucleotide polymorphisms (SNPs) are the most common forms of sequence variations in the human genome. They contribute to the human phenotypic spectrum and are associated with variations in response to pathogens, drugs and vaccines. Recently, SNPs in three human genes involved in kidney development (RET, PAX2 and ALDH1A2) have been reported to be associated with variation in renal size and function. These known SNPs could potentially be used in the clinic as markers for identifying babies who may have smaller kidneys and permit close follow up for early detection of hypertension and acquired renal dysfunction. The aim of this study was to evaluate the use of High Resolution Melting technique (HRM) as a tool for detecting the known SNPs in these three genes in comparison to sequencing which is the gold standard. Methods High resolution melting analysis was performed on 75 DNA samples that were previously sequenced for the known polymorphisms in RET (rs1800860), PAX2 (rs11190688) and ALDH1A2 (rs7169289) genes. The SNPs were G > A transitions in RET and PAX2 and A > G in ALDH1A2 gene. A blinded assessment was performed on these samples for evaluation of the HRM technique as compared to sequencing. Results Each variant had a unique melt curve profile that was reproducible. The shift in melting temperature (Tm) allowed visual discrimination between the homozygous alleles (major and minor) in all three genes. The shape of the melting curve as compared to the major allele homozygous curve allowed the identification of the heterozygotes in each of the three SNPs. For validation, HRM was performed on 25 samples for each of the three SNPs. The results were compared with the sequencing results and 100% correct identification of the samples was obtained for RET, PAX2, and ALDA1H2 gene. Conclusion High Resolution Melting analysis is a simple, rapid and cost effective technique that could be used in a large population to identify babies with the risk alleles. These high risk children could be followed up for early detection of hypertension and acquired renal dysfunction.