Nitric oxide synthase gene polymorphisms in children with minimal change nephrotic syndrome

Single Nucleotide Polymorphisms in Pediatric Idiopathic Nephrotic Syndrome

Polymorphic variants in several molecules involved in the glomerular function and drug metabolism have been implicated in the pathophysiology of pediatric idiopathic nephrotic syndrome (INS), but the results remain inconsistent. We analyzed the association of eleven allelic variants in eight genes (angiopoietin-like 4 (ANGPTL4), glypican 5 (GPC5), interleukin-13 (IL-13), macrophage migration inhibitory factor (MIF), neural nitric oxide synthetase (nNOS), multidrug resistance-1 (MDR1), glucocorticoid-induced transcript-1 (GLCCI1), and nuclear receptor subfamily-3 (NR3C1)) in 100 INS patients followed up till adulthood. We genotyped variants using PCR and direct sequencing and evaluated estimated haplotypes of MDR1 variants. The analysis revealed few differences in SNP genotype frequencies between patients and controls, or in clinical parameters among the patients. Genotype distribution of MDR1 SNPs rs1236, rs2677, and rs3435 showed significant (p < 0.05) association with different medication regimes (glucocorticoids only versus glucocorticoids plus additional immunosuppressives). Some marginal association was detected between ANGPTL4, GPC5, GLCCI1, and NR3C1 variants and different medication regimes, number of relapses, and age of onset. Conclusion. While MDR1 variant genotype distribution associated with different medication regimes, the other analyzed gene variants showed only little or marginal clinical relevance in INS.

Association of eNOS gene intron 4 a/b VNTR polymorphisms in children with nephrotic syndrome

To investigate the association of endothelial nitric oxide synthase gene intron 4 (eNOS4) polymorphisms with nephrotic syndrome, the eNOS4 genotypes were assessed in 161 children with nephrotic syndrome in comparison with 78 healthy subjects. We classified the children with nephritic syndrome into 2 groups: as steroid-sensitive nephrotic syndrome (SSNS) (n=125) and steroid-resistant nephrotic syndrome (SRNS) (n=36). The eNOS4 polymorphisms were analyzed by polymerase chain reaction. The frequencies of eNOS4 aa, ab and bb genotypes were 3%, 31%, and 66% in all the nephrotic syndrome groups, and 1%, 23%, and 76% in the control group (x(2)=2.87, p>0.05). In addition, the frequencies of eNOS4 aa, ab and bb genotypes were 2%, 33%, and 65% in SSNS group, and 5%, 28%, and 67% in the SRNS group (x(2)=1.13, p=0.567). The present study is the first to investigate eNOS4 gene polymorphisms in children with SSNS and SRNS. Our data show that the eNOS4 gene polymorphisms were not associated with the development, frequent relapse and response to steroid in nephritic syndrome.

Lack of association between the C276T polymorphism of the neuronal nitric oxide synthase gene and migraine

A migraine attack is a spectacularly complex brain event that can produce a wide array of neurological and systemic symptoms. The molecular mechanisms and genetics of migraine have not yet been clarified. The objective of this study was to analyze the genotype distributions and allele frequencies for the C276T polymorphism of the neuronal nitric oxide synthase (nNOS) gene among the patients with migraine. The diagnosis of migraine was made clinically based on questionnaires. One hundred and twenty patients with migraine were genotyped for the C276T polymorphism of the nNOS gene and compared with 185 age-matched healthy controls. Genomic DNA from migraine patients and controls was analyzed by polymerase chain reaction (PCR). A PCR-restriction fragment-length polymorphism analysis of nNOS gene polymorphism was performed, and the results were compared. Neither genotype distributions nor the allele frequencies for the C276T polymorphism showed a significant difference between the groups. Additionally, there was no marked differences in genotype distribution or allele frequencies for the migraine without aura and migraine with aura subgroups when compared to control group. These results suggested that migraine of the Turkish population seemed to develop without any alterations in nNOS C276T polymorphism. Our data showed that there is no marked association between the C276T polymorphism of the nNOS gene and migraine.

Relationship between Angiotensin-Converting Enzyme Insertion/Deletion Gene Polymorphism and Susceptibility of Minimal Change Nephrotic Syndrome: A Meta-Analysis

Aim. This meta-analysis was performed to evaluate the association between ACE I/D gene polymorphism and MCNS susceptibility. Method. A predefined literature search and selection of eligible relevant studies were performed to collect the data from electronic databases. Results. Six articles were identified for the analysis of association between ACE I/D gene polymorphism and MCNS risk, including 4 for Asians, one in Caucasian population and one for Africans. There was a markedly positive association between D allele or DD genotype and MCNS susceptibility in Asians (D: P = .01, DD: P = .02), but not for Caucasians and Africans (Caucasians: D: P = .16, DD: P = .98; Africans: D: P = .81, DD: P = .49). Furthermore, the II genotype seemed not to play a protective role against MCNS risk for Asians, Caucasians and Africans (P = .12, P = .09, P = .76, resp.). Interestingly, there was also significant association between ACE I/D gene polymorphism and MCNS susceptibility in overall populations (D: P = .007, DD: P = .04, II: P = .03). Conclusion. D allele or DD genotype might be a significant genetic molecular marker for MCNS susceptibility in Asians and overall populations, but not for Caucasians and Africans. More larger and rigorous genetic epidemiological investigations are required to further explore this association.

Phosphodiesterase-5 gene (PDE5A) polymorphisms are associated with progression of childhood IgA nephropathy

The phosphodiesterase-5 (PDE-5) gene is highly specific to cyclic GMP (cGMP) and several experimental studies have shown that the nitric oxide/cGMP pathway plays an important role in the pathogenesis of glomerulonephritis, including IgA nephropathy (IgAN). The present study was conducted to investigate the association among 16 single nucleotide polymorphisms (SNPs) of PDE5A and childhood IgAN. The genotyping data from 160 patients with childhood IgAN and 454 controls showed a significant difference in rs13124532 (codominant, P = 0.005; dominant, P = 0.005). Furthermore, patient subgroup analysis revealed an association between the development of proteinuria (>4 and <or=4 mg/m(2)/h) and rs13124532 (codominant, P = 0.008; dominant, P = 0.011), and between the nephrotic range proteinuria (> 40 mg/m(2)/h) and rs11734241 (dominant, P = 0.035), rs12510138 (dominant, P = 0.028), rs13134665 (dominant, P = 0.025), rs3822192 (dominant, P = 0.027), rs10013305 (dominant, P = 0.020), rs1480940 (dominant, P = 0.020), rs1480936 (dominant, P = 0.019), rs11947234 (dominant, P = 0.019), and rs2127823 (dominant, P = 0.026). The pathological findings showed that rs13124532 had an association with podocyte foot process effacement (codominant, P = 0.035; dominant, P = 0.044) and with pathological progression (codominant, P = 0.046). Our results suggest that PDE5A is associated with increased disease susceptibility, pathological progression, and development of proteinuria in childhood IgAN.