The aim of this study is to investigate the blood pressure (BP) profile, microalbuminuria, renal functions, and relations with remaining normal kidney size in children with unilateral functioning solitary kidney (UFSK). Sixtysix children with UFSK were equally divided into three groups: unilateral renal agenesis (URA), unilateral atrophic kidney (UAK), and unilateral nephrectomy (UNP). Twentytwo age-, weight-, and height-matched healthy children were considered as a control group. The serum creatinine level and first-morning urine microalbumin and creatinine concentrations were determined by the standard methods. Also, the BP profile was determined by ambulatory blood pressure monitoring (ABPM). We found that the serum creatinine level was higher and creatinine clearance was lower in each patient groups compared to those of the control group (p<0.05). Compared with the controls, each group of patients had mean office, 24-h, daytime, and night-time systolic and diastolic BP values similar to those of the controls (p>0.05). An inverse correlation was found between the renal size standard deviation scores (SDS) of normal kidneys and 24-h systolic and diastolic BP load SDS in all of the patients (p<0.05; r=−0.372, r=−0.295, respectively). The observed relationship between renal size SDS and 24-h mean arterial pressure (MAP), systolic and diastolic BP load SDS suggests that children with UFSK should be evaluated by using ABPM for the risk of hypertension.

Idiopathic nephrotic syndrome (INS) is a genetically heterogeneous group of disorders characterized by proteinuria, hypoalbuminemia, and edema. Because it typically results in end-stage kidney disease, the steroid-resistant subtype (SRNS) of INS is especially important when it occurs in children. The present study included 29 affected and 22 normal individuals from 17 SRNS families; genome-wide analysis was performed with Affymetrix 250K SNP arrays followed by homozygosity mapping. A large homozygous stretch on chromosomal region 12p12 was identified in one consanguineous family with two affected siblings. Direct sequencing of protein tyrosine phosphatase receptor type O (PTPRO; also known as glomerular epithelial protein-1 [GLEPP1]) showed homozygous c.2627+1G>T donor splice-site mutation. This mutation causes skipping of the evolutionarily conserved exon 16 (p.Glu854_Trp876del) at the RNA level. Immunohistochemistry with GLEPP1 antibody showed a similar staining pattern in the podocytes of the diseased and control kidney tissues. We used a highly polymorphic intragenic DNA marker-D12S1303-to search for homozygosity in 120 Turkish and 13 non-Turkish individuals in the PodoNet registry. This analysis yielded 17 candidate families, and a distinct homozygous c.2745+1G>A donor splice-site mutation in PTPRO was further identified via DNA sequencing in a second Turkish family. This mutation causes skipping of exon 19, and this introduces a premature stop codon at the very beginning of exon 20 (p.Asn888Lysfs*3) and causes degradation of mRNA via nonsense-mediated decay. Immunohistochemical analysis showed complete absence of immunoreactive PTPRO. Ultrastructural alterations, such as diffuse foot process fusion and extensive microvillus transformation of podocytes, were observed via electron microscopy in both families. The present study introduces mutations in PTPRO as another cause of autosomal-recessive nephrotic syndrome.

Congenital solitary functioning kidney (CSFK) is a relatively common renal malformation and in children is frequently complicated by anomalies of the ipsilateral genital organs and occasionally by anomalies of other organs. The aim of this study was to determine the incidence of associated urological, cardiac, gastrointestinal, hematological, neurological, skeletal, and other congenital malformations in children with CSFK. We retrospectively reviewed 87 consecutive cases of CSFK diagnosed at our hospital between 1995 and 2003. There were 45 boys and 42 girls, whose ages at diagnosis ranged from newborn to 16 years (mean 4.67+/-4.48 years). In all patients, CSFK was diagnosed by abdominal ultrasound and confirmed by radionuclide studies. In 46 patients (53%) the left kidney was absent, and in 41 patients (47%) the right kidney was absent. Overall associated anomalies were detected in 52 of the 87 children (60%) with CSFK. Urological anomalies were most common, with an incidence of 37% (32/87). Nonurological anomalies were detected in 38 children (44%) with CSFK; these included cardiac anomalies in 13, gastrointestinal anomalies in eight, hematological anomalies in five, neurological anomalies in three, and other organ anomalies in nine. In our study, more than half of the patients with CSFK had associated anomalies. For this reason we recommend abdominal ultrasound and voiding cystourethrogram for early recognition of urological anomalies and a careful physical examination for other organ anomalies in patients with CSFK.

These results indicate that GH deficiency may contribute to short stature in children with Bartter syndrome, and rhGH therapy would be an excellent adjunctive treatment for short children with this syndrome whose condition is resistant to conventional therapies in terms of growth.

Although the prognosis of APSGN in children is good, severe systemic complications and renal failure may develop during the follow-up period. Decreased C4, presence of hypoalbuminemia, and increased inflammatory markers (WBC, CRP, neutrophil count and NLR) might be possible risk factors for severity of renal involvement. Decreased C4, in particular, may be a risk factor for decreased GFR in those children.