NR3C1 gene polymorphism for genetic susceptibility to infantile spasms in a Chinese population

NR3C1 variants and glucocorticoid response in childhood nephrotic syndrome in North India

BACKGROUND

Nephrotic syndrome (NS) is a common kidney disorder in children, characterized by significant proteinuria, hypoalbuminemia, and peripheral edema. While glucocorticoids (GCs) are the first-line treatment for pediatric nephrotic syndrome (NS), a subset of patients exhibit steroid resistance, leading to poor prognosis and a higher risk of long-term kidney damage. The glucocorticoid receptor gene (NR3C1) plays a pivotal role in mediating the effects of GCs, and its polymorphisms have been implicated in variable GC responses.

METHODS

This study investigates the association between NR3C1 single nucleotide polymorphisms (SNPs) (rs6877893 and rs10482634) in 50 patients with steroid-sensitive nephrotic syndrome (SSNS) and 50 steroid-resistant nephrotic syndrome (SRNS) individuals by Kompetitive Allele Specific Polymerase Chain Reaction (KASP) assay and altered GC receptors (GRα and GRβ) expression by Real-Time PCR (RT-PCR). Adverse effect of steroid therapy was also assessed.

RESULTS

Genotyping revealed a significant association between GG genotype of SNP rs10482634 and steroid resistance, suggesting that it may contribute to the heterogeneity in GC response in this population. There is also a positive association of AA genotype of rs10482634 with short stature and AG genotype of rs10482634 with cushingoid habitus, as a side effect of steroid therapy. We have also found an enhanced expression of GRα in SSNS population. No significant association was found between the SNP rs6877893 and the response to steroid treatment in the study cohort. Our study revealed higher rates of drug-related complications in patients receiving larger cumulative doses of steroids.

CONCLUSION

These findings highlight the importance of genetic screening of NR3C1 SNPs in predicting steroid responsiveness and tailoring personalized therapeutic strategies in pediatric NS.

CLINICAL TRIAL NUMBER

not applicable.

Assessment of the Link of ABCB1 and NR3C1 gene polymorphisms with the prednisolone resistance in pediatric nephrotic syndrome patients of Bangladesh: A genotype and haplotype approach

Introduction

Nephrotic syndrome is a common pediatric kidney disease. Investigations on several genetic polymorphisms revealed an inconsistent influence on the resistance of patients to steroids.

Objectives

This study aimed to identify the association of ABCB1 (1236C > T, 2677G > T, 3435C > T), NR3C1 (rs10482634, rs6877893), and CYP3A5 (CYP3A5*3) gene polymorphism as well as sociodemographic and clinicopathological parameters with the risk of developing prednisolone resistance in pediatric patients with nephrotic syndrome.

Methods

A case-control analysis was performed on 180 nephrotic syndrome patients. Among them, 30 patients were classified as prednisolone resistant group, and 150 were classified as prednisolone sensitive group. Genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Results

No significant association of 1236C > T polymorphism with the risk of prednisolone resistance (p > 0.05) was found. The GT heterozygous of 2677G > T was found to be significantly associated with the development of prednisolone resistance (OR = 3.9, p = 0.034). In the case of 3435C > T, a statistically significant association was observed in TC heterozygous and TT mutant homozygous genotypes (OR = 0.38, p = 0.047; OR = 3.06, p = 0.038, respectively) with prednisolone resistance. For rs10482634 polymorphism, the AG heterozygous and AG+GG genotypes were significantly linked with prednisolone resistance (OR = 2.40, p = 0.033; OR = 2.36, p = 0.034, respectively). We found no association with the risk of prednisolone resistance with rs6877893 and CYP3A5*3 polymorphism (p > 0.05). CTC and TGT haplotypes of ABCB1 and GA haplotype of NR3C1 were also associated with the increased risk of pediatric prednisolone resistance (OR = 4.47, p = 0.0003; OR = 2.71, p = 0.03; and OR = 4.22, p = 0.022, consecutively). We also observed the correlation of different sociodemographic and clinicopathological factors with prednisolone resistance in pediatric nephrotic syndrome.

Conclusion

Our findings showed a significant association of ABCB1 and NR3C1 gene polymorphisms with prednisolone resistant pediatric nephrotic syndrome.

Association analysis of polymorphisms of the CRHR1 gene with infantile spasms

While >200 types of etiologies have been shown to be involved in the pathogenesis of infantile spasms, the pathophysiology of infantile spasms remains largely elusive. Pre-natal stress and hypothalamic-pituitary-adrenal axis dysfunction were shown to be involved in the development of infantile spasms. To test the genetic association between the CRHR1 gene, which encodes the corticotrophin-releasing hormone (CRH) receptor, and infantile spasms, five single nucleotide polymorphisms (SNPs) in the CRHR1 gene were genotyped in a sample set of 128 cases with infantile spasms and 131 healthy controls. Correlation analysis was performed on the genotyped data. Under the assumption of the dominant model, the selected five SNPs, rs4458044, rs171440, rs17689966, rs28364026 and rs242948, showed no association with the risk of infantile spasms and the effectiveness of adrenocorticotropic hormone treatment. In addition, subsequent haplotype analysis suggested none of them was associated with infantile spasms. In conclusion, the experimental results of the present study suggested no association between the CRHR1 gene and infantile spasms in a Chinese population.

An effective initial polytherapy for children with West syndrome

Adrenocorticotropic hormone is recommended worldwide as an initial therapy for infantile spasms. However, infantile spasms in about 50% of children cannot be fully controlled by adrenocorticotropic hormone monotherapy, seizures recur in 33% of patients who initially respond to adrenocorticotropic hormone monotherapy, and side effects are relatively common during adrenocorticotropic hormone treatment. Topiramate, vitamin B₆, and immunoglobulin are effective in some children with infantile spasms. In the present study, we hypothesized that combined therapy with adrenocorticotropic hormone, topiramate, vitamin B₆, and immunoglobulin would effectively treat infantile spasms and have mild adverse effects. Thus, 51 children newly diagnosed with West syndrome including infantile spasms were enrolled and underwent polytherapy with the four drugs. Electroencephalographic hypsarrhythmia was significantly improved in a majority of patients, and these patients were seizure-free, had mild side effects, and low recurrence rates. The overall rates of effective treatment and loss of seizures were significantly higher in cryptogenic children compared with symptomatic children. The mean time to loss of seizures in cryptogenic children was significantly shorter than in symptomatic patients. These findings indicate that initial polytherapy with adrenocorticotropic hormone, topiramate, vitamin B₆, and immunoglobulin effectively improves the prognosis of infantile spasms, and its effects were superior in cryptogenic children to symptomatic children.