Background and objectives Steroid-resistant nephrotic syndrome is a rare kidney disease involving either immune-mediated or genetic alterations of podocyte structure and function. The rare nature, heterogeneity, and slow evolution of the disorder are major obstacles to systematic genotype-phenotype, intervention, and outcome studies, hampering the development of evidence-based diagnostic and therapeutic concepts. To overcome these limitations, the PodoNet Consortium has created an international registry for congenital nephrotic syndrome and childhood-onset steroid-resistant nephrotic syndrome.

It was demonstrated that although the Tel Hashomer criteria were successful in diagnosing the FMF patients in childhood, its specificity was definitely low in children. The new set of criteria has a high sensitivity and specificity for the diagnosis of FMF and is practical to use on an everyday basis.

None of the four missense mutations is associated with a severe disease or the development of amyloidosis in Turkish FMF patients living in Turkey. The influence of unknown environmental factors and/or the presence of other genetic changes are necessary to explain the phenotypic variation of the disease and the development of amyloidosis.

Alterations in the MEFV gene are important susceptibility factors for the development of HSP and also affect the clinical presentation of it.

In order to obtain data on blood pressure (BP) distribution in Turkish children, a total of 5,599 Turkish children from birth to 18 years were studied. BP rises with age, and both systolic and diastolic BP showed a positive correlation with height and weight in both sexes. As the sampling was representative of Turkish children at different ages, the mean systolic and diastolic BP levels were compared for each age with the results reported in the study of the Second Task Force. The mean systolic and diastolic BP of Turkish children and the increase with growth and development were different from the Second Task Force study. Genetic, ethnic, and environmental factors were suggested to be responsible for this variation. In conclusion, normal BP curves should be applied with caution in childhood, and every population should use their own normal standards to define a measured BP level in children.

Familial Mediterranean Fever (FMF) is an autosomal recessive disease characterized by recurrent self‐limited attacks of fever accompanied by peritonitis, pleuritis and arthritis. Approximately 5% of individuals with FMF have been reported to have Henoch‐Schonlein purpura (HSP) and about 1% have polyarteritis nodosa (PAN). Protracted febrile myalgia is another vasculitis‐associated clinical entity among patients with FMF. Recently, the gene responsible for FMF, MEFV, has been cloned and four missense mutations (M680I, M694V, V726A and M694I) have been described. In this report, we present clinical and laboratory findings and mutation results of 23 children with FMF‐associated vasculitis. HSP, PAN and protracted febrile attacks have been diagnosed in 11, 2 and 10 children, respectively. Mutation analysis shows that 3 children are homozygotes for the M694V mutation and 11 are compound heterozygotes for 2 of the studied mutations. M694V/V726A mutations were identified in 8, M694V/M694I in 2 and M680I/M694V in 1 of these children. In six children only one mutation was found and in three none of the studied mutations were identified. This study confirms that most children with FMF‐associated vasculitis have identifiable mutations in the MEFV gene. Environmental and/or other genetic factors are possibly involved in the pathogenesis of vasculitis in FMF; elucidation of these mechanisms will help to understand pathogenesis of childhood vasculitides. ?Children, Familial Mediterranean Fever, MEFV mutations, vasculitis

The podocin (NPHS2) gene encodes podocin protein, which has an important role in glomerular ultrafiltration and controlling slit membrane permeability. The detection of an NPHS2 mutation affects the treatment plan for children with nephritic syndrome (NS). The frequency and spectrum of podocin mutations in the Turkish population have remained largely unknown. The aim of this study was to screen for podocin mutations in Turkish patients with steroid-resistant NS (SRNS) and to compare it with other published series. There were 295 children with SRNS, originating from Turkey, included in this study. Forty-one patients (13.8%) had familial NS and 254 patients (86.2%) had sporadic NS. Mutation analysis was performed in all eight exons of the NPHS2 gene with the direct DNA sequencing method. There were 53 different pathogenetic NPHS2 mutations detected, including 37 novel mutations. The mutation detection rate was 24.7% for all patients, 29.2% for familial, and 24% for sporadic SRNS. The most common mutated exon was exon 5 (52 allele). The presence of mutations in exon 4 was found to increase the risk of end-stage renal disease (ESRD). Among patients with mutations, the rates of renal failure and/or ESRD (26%) were significantly higher than in those without mutations (12.6%). The mean time of progression to renal failure and ESRD in patients with mutations (1.8 +/- 2.5 years) was significantly shorter than in patients without mutations (3.7 +/- 4.0 years). Additionally, in patients with heterozygote mutations, fewer cases (13.6%) progressed to renal failure and/or ESRD than in with patients who had homozygote/compound heterozygote mutations (31.3%). In conclusion, podocin mutations are responsible for some of both familial and sporadic SRNS cases in Turkey. The mutations in this gene should be searched for in every child after presentation with the first episode of NS.

We suggest that FMF, perhaps as a consequence of impaired control of inflammatory responses, predisposes to vasculitis with renal involvement.