Sean Ennis

University College Dublin, Dublin, L, Ireland (Republic of Ireland)

Are you Sean Ennis?

Claim your profile

Publications (20)214.67 Total impact

  • Source
    Article: Individual common variants exert weak effects on the risk for autism spectrum disorderspi.
    [show abstract] [hide abstract]
    ABSTRACT: While it is apparent that rare variation can play an important role in the genetic architecture of autism spectrum disorders (ASDs), the contribution of common variation to the risk of developing ASD is less clear. To produce a more comprehensive picture, we report Stage 2 of the Autism Genome Project genome-wide association study, adding 1301 ASD families and bringing the total to 2705 families analysed (Stages 1 and 2). In addition to evaluating the association of individual single nucleotide polymorphisms (SNPs), we also sought evidence that common variants, en masse, might affect the risk. Despite genotyping over a million SNPs covering the genome, no single SNP shows significant association with ASD or selected phenotypes at a genome-wide level. The SNP that achieves the smallest P-value from secondary analyses is rs1718101. It falls in CNTNAP2, a gene previously implicated in susceptibility for ASD. This SNP also shows modest association with age of word/phrase acquisition in ASD subjects, of interest because features of language development are also associated with other variation in CNTNAP2. In contrast, allele scores derived from the transmission of common alleles to Stage 1 cases significantly predict case status in the independent Stage 2 sample. Despite being significant, the variance explained by these allele scores was small (Vm< 1%). Based on results from individual SNPs and their en masse effect on risk, as inferred from the allele score results, it is reasonable to conclude that common variants affect the risk for ASD but their individual effects are modest.
    Human Molecular Genetics 07/2012; 21(21):4781-92. · 7.64 Impact Factor
  • Article: Identification of a mutation in LARS as a novel cause of infantile hepatopathy.
    [show abstract] [hide abstract]
    ABSTRACT: Infantile hepatopathies are life-threatening liver disorders that manifest in the first few months of life. We report on a consanguineous Irish Traveller family that includes six individuals presenting with acute liver failure in the first few months of life. Additional symptoms include anaemia, renal tubulopathy, developmental delay, seizures, failure to thrive and deterioration of liver function with minor illness. The multisystem manifestations suggested a possible mitochondrial basis to the disorder. However, known causes of childhood liver failure and mitochondrial disease were excluded in this family by biochemical, metabolic and genetic analyses. We aimed to identify the underlying risk gene using homozygosity mapping and whole exome sequencing. SNP homozygosity mapping identified a candidate locus at 5q31.3-q33.1. Whole exome sequencing identified 1 novel homozygous missense mutation within the 5q31.3-q33.1 candidate region that segregated with the hepatopathy. The candidate mutation is located in the LARS gene which encodes a cytoplasmic leucyl-tRNA synthetase enzyme responsible for exclusively attaching leucine to its cognate tRNA during protein translation. Knock-down of LARS in HEK293 cells did not impact on mitochondrial function even when the cells were put under physiological stress. The molecular studies confirm the findings of the patients' biochemical and genetic analyses which show that the hepatopathy is not a mitochondrial-based dysfunction problem, despite clinical appearances. This study highlights the clinical utility of homozygosity mapping and exome sequencing in diagnosing recessive liver disorders. It reports mutation of a cytoplasmic aminoacyl-tRNA synthetase enzyme as a possible novel cause of infantile hepatopathy and underscores the need to consider mutations in LARS in patients with liver disease and multisystem presentations.
    Molecular Genetics and Metabolism 04/2012; 106(3):351-8. · 3.19 Impact Factor
  • Article: Recessive mutations in MCM4/PRKDC cause a novel syndrome involving a primary immunodeficiency and a disorder of DNA repair.
    [show abstract] [hide abstract]
    ABSTRACT: A study is presented of 10 children with a novel syndrome born to consanguineous parents from the Irish Traveller population. The syndrome is characterised by a natural killer (NK) cell deficiency, evidence of an atypical Fanconi's type DNA breakage disorder, and features of familial glucocorticoid deficiency (FGD). The NK cell deficiency probably accounts for the patients' recurrent viral illnesses. Molecular tests support a diagnosis of mosaic Fanconi's anaemia, but the patients do not present with any of the expected clinical features of the disorder. The symptomatic presentation of FGD was delayed in onset and may be a secondary phenotype. As all three phenotypes segregate together, the authors postulated that the NK cell deficiency, DNA repair disorder and FGD were caused by a single recessive genetic event. Single-nucleotide polymorphism homozygosity mapping and targeted next-generation sequencing of 10 patients and 16 unaffected relatives. A locus for the syndrome was identified at 8p11.21-q11.22. Targeted resequencing of the candidate region revealed a homozygous mutation in MCM4/PRKDC in all 10 affected individuals. Consistent with the observed DNA breakage disorder, MCM4 and PRKDC are both involved in the ATM/ATR (ataxia-telangiectasia-mutated/ATM-Rad 3-related) DNA repair pathway, which is defective in patients with Fanconi's anaemia. Deficiency of PRKDC in mice has been shown to result in an abnormal NK cell physiology similar to that observed in these patients. Mutations in MCM4/PRKDC represent a novel cause of DNA breakage and NK cell deficiency. These findings suggest that clinicians should consider this disorder in patients with failure to thrive who develop pigmentation or who have recurrent infections.
    Journal of Medical Genetics 04/2012; 49(4):242-5. · 6.36 Impact Factor
  • Article: HGDP and HapMap Analysis by Ancestry Mapper Reveals Local and Global Population Relationships.
    [show abstract] [hide abstract]
    ABSTRACT: Knowledge of human origins, migrations, and expansions is greatly enhanced by the availability of large datasets of genetic information from different populations and by the development of bioinformatic tools used to analyze the data. We present Ancestry Mapper, which we believe improves on existing methods, for the assignment of genetic ancestry to an individual and to study the relationships between local and global populations. The principle function of the method, named Ancestry Mapper, is to give each individual analyzed a genetic identifier, made up of just 51 genetic coordinates, that corresponds to its relationship to the HGDP reference population. As a consequence, the Ancestry Mapper Id (AMid) has intrinsic biological meaning and provides a tool to measure similarity between world populations. We applied Ancestry Mapper to a dataset comprised of the HGDP and HapMap data. The results show distinctions at the continental level, while simultaneously giving details at the population level. We clustered AMids of HGDP/HapMap and observe a recapitulation of human migrations: for a small number of clusters, individuals are grouped according to continental origins; for a larger number of clusters, regional and population distinctions are evident. Calculating distances between AMids allows us to infer ancestry. The number of coordinates is expandable, increasing the power of Ancestry Mapper. An R package called Ancestry Mapper is available to apply this method to any high density genomic data set.
    PLoS ONE 01/2012; 7(11):e49438. · 4.09 Impact Factor
  • Source
    Article: A novel approach of homozygous haplotype sharing identifies candidate genes in autism spectrum disorder.
    [show abstract] [hide abstract]
    ABSTRACT: Autism spectrum disorder (ASD) is a highly heritable disorder of complex and heterogeneous aetiology. It is primarily characterized by altered cognitive ability including impaired language and communication skills and fundamental deficits in social reciprocity. Despite some notable successes in neuropsychiatric genetics, overall, the high heritability of ASD (~90%) remains poorly explained by common genetic risk variants. However, recent studies suggest that rare genomic variation, in particular copy number variation, may account for a significant proportion of the genetic basis of ASD. We present a large scale analysis to identify candidate genes which may contain low-frequency recessive variation contributing to ASD while taking into account the potential contribution of population differences to the genetic heterogeneity of ASD. Our strategy, homozygous haplotype (HH) mapping, aims to detect homozygous segments of identical haplotype structure that are shared at a higher frequency amongst ASD patients compared to parental controls. The analysis was performed on 1,402 Autism Genome Project trios genotyped for 1 million single nucleotide polymorphisms (SNPs). We identified 25 known and 1,218 novel ASD candidate genes in the discovery analysis including CADM2, ABHD14A, CHRFAM7A, GRIK2, GRM3, EPHA3, FGF10, KCND2, PDZK1, IMMP2L and FOXP2. Furthermore, 10 of the previously reported ASD genes and 300 of the novel candidates identified in the discovery analysis were replicated in an independent sample of 1,182 trios. Our results demonstrate that regions of HH are significantly enriched for previously reported ASD candidate genes and the observed association is independent of gene size (odds ratio 2.10). Our findings highlight the applicability of HH mapping in complex disorders such as ASD and offer an alternative approach to the analysis of genome-wide association data.
    Human Genetics 10/2011; 131(4):565-79. · 5.07 Impact Factor
  • Article: First implication of STRA6 mutations in isolated anophthalmia, microphthalmia, and coloboma: a new dimension to the STRA6 phenotype.
    [show abstract] [hide abstract]
    ABSTRACT: Microphthalmia, anophthalmia, and coloboma (MAC) are structural congenital eye malformations that cause a significant proportion of childhood visual impairments. Several disease genes have been identified but do not account for all MAC cases, suggesting that additional risk loci exist. We used single nucleotide polymorphism (SNP) homozygosity mapping (HM) and targeted next-generation sequencing to identify the causative mutation for autosomal recessive isolated colobomatous microanophthalmia (MCOPCB) in a consanguineous Irish Traveller family. We identified a double-nucleotide polymorphism (g.1157G>A and g.1156G>A; p.G304K) in STRA6 that was homozygous in all of the MCOPCB patients. The STRA6 p.G304K mutation was subsequently detected in additional MCOPCB patients, including one individual with Matthew-Wood syndrome (MWS; MCOPS9). STRA6 encodes a transmembrane receptor involved in vitamin A uptake, a process essential to eye development and growth. We have shown that the G304K mutant STRA6 protein is mislocalized and has severely reduced vitamin A uptake activity. Furthermore, we reproduced the MCOPCB phenotype in a zebrafish disease model by inhibiting retinoic acid (RA) synthesis, suggesting that diminished RA levels account for the eye malformations in STRA6 p.G304K patients. The current study demonstrates that STRA6 mutations can cause isolated eye malformations in addition to the congenital anomalies observed in MWS.
    Human Mutation 09/2011; 32(12):1417-26. · 5.69 Impact Factor
  • Source
    Article: Functional impact of global rare copy number variation in autism spectrum disorders.
    [show abstract] [hide abstract]
    ABSTRACT: The autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in reciprocal social interaction and communication, and the presence of restricted and repetitive behaviours. Individuals with an ASD vary greatly in cognitive development, which can range from above average to intellectual disability. Although ASDs are known to be highly heritable ( approximately 90%), the underlying genetic determinants are still largely unknown. Here we analysed the genome-wide characteristics of rare (<1% frequency) copy number variation in ASD using dense genotyping arrays. When comparing 996 ASD individuals of European ancestry to 1,287 matched controls, cases were found to carry a higher global burden of rare, genic copy number variants (CNVs) (1.19 fold, P = 0.012), especially so for loci previously implicated in either ASD and/or intellectual disability (1.69 fold, P = 3.4 x 10(-4)). Among the CNVs there were numerous de novo and inherited events, sometimes in combination in a given family, implicating many novel ASD genes such as SHANK2, SYNGAP1, DLGAP2 and the X-linked DDX53-PTCHD1 locus. We also discovered an enrichment of CNVs disrupting functional gene sets involved in cellular proliferation, projection and motility, and GTPase/Ras signalling. Our results reveal many new genetic and functional targets in ASD that may lead to final connected pathways.
    Nature 07/2011; 466:368-372. · 36.28 Impact Factor
  • Article: Agenesis of the corpus callosum with midline lipoma associated with an Xp22.31-Xp22.12 deletion.
    Clinical dysmorphology 01/2011; 20(1):21-5. · 0.47 Impact Factor
  • Source
    Article: The 12q14 microdeletion syndrome: six new cases confirming the role of HMGA2 in growth.
    [show abstract] [hide abstract]
    ABSTRACT: We report six patients with array deletions encompassing 12q14. Out of a total of 2538 array investigations carried out on children with developmental delay and dysmorphism in three diagnostic testing centres, six positive cases yielded a frequency of 1 in 423 for this deletion syndrome. The deleted region in each of the six cases overlaps significantly with previously reported cases with microdeletions of this region. The chromosomal range of the deletions extends from 12q13.3q15. In the current study, we report overlapping deletions of variable extent and size but primarily comprising chromosomal bands 12q13.3q14.1. Four of the six deletions were confirmed as de novo events. Two cases had deletions that included HMGA2, and both children had significant short stature. Neither case had osteopoikilosis despite both being deleted for LEMD3. Four cases had deletions that ended proximal to HMGA2 and all of these had much better growth. Five cases had congenital heart defects, including two with atrial septal defects, one each with pulmonary stenosis, sub-aortic stenosis and a patent ductus. Four cases had moderate delay, two had severe developmental delay and a further two had a diagnosis of autism. All six cases had significant speech delay with subtle facial dysmorphism.
    European journal of human genetics: EJHG 01/2011; 19(5):534-9. · 3.56 Impact Factor
  • Source
    Article: A genome-wide scan for common alleles affecting risk for autism.
    [show abstract] [hide abstract]
    ABSTRACT: Although autism spectrum disorders (ASDs) have a substantial genetic basis, most of the known genetic risk has been traced to rare variants, principally copy number variants (CNVs). To identify common risk variation, the Autism Genome Project (AGP) Consortium genotyped 1558 rigorously defined ASD families for 1 million single-nucleotide polymorphisms (SNPs) and analyzed these SNP genotypes for association with ASD. In one of four primary association analyses, the association signal for marker rs4141463, located within MACROD2, crossed the genome-wide association significance threshold of P < 5 × 10(-8). When a smaller replication sample was analyzed, the risk allele at rs4141463 was again over-transmitted; yet, consistent with the winner's curse, its effect size in the replication sample was much smaller; and, for the combined samples, the association signal barely fell below the P < 5 × 10(-8) threshold. Exploratory analyses of phenotypic subtypes yielded no significant associations after correction for multiple testing. They did, however, yield strong signals within several genes, KIAA0564, PLD5, POU6F2, ST8SIA2 and TAF1C.
    Human Molecular Genetics 10/2010; 19(20):4072-82. · 7.64 Impact Factor
  • Source
    Article: A genome-wide scan for common alleles affecting risk for autism.
    [show abstract] [hide abstract]
    ABSTRACT: Although autism spectrum disorders (ASDs) have a substantial genetic basis, most of the known genetic risk has been traced to rare variants, principally copy number variants (CNVs). To identify common risk variation, the Autism Genome Project (AGP) Consortium genotyped 1558 rigorously defined ASD families for 1 million single-nucleotide polymorphisms (SNPs) and analyzed these SNP genotypes for association with ASD. In one of four primary association analyses, the association signal for marker rs4141463, located within MACROD2, crossed the genome-wide association significance threshold of P < 5 x 10(-8). When a smaller replication sample was analyzed, the risk allele at rs4141463 was again over-transmitted; yet, consistent with the winner's curse, its effect size in the replication sample was much smaller; and, for the combined samples, the association signal barely fell below the P < 5 x 10(-8) threshold. Exploratory analyses of phenotypic subtypes yielded no significant associations after correction for multiple testing. They did, however, yield strong signals within several genes, KIAA0564, PLD5, POU6F2, ST8SIA2 and TAF1C.
    Human Molecular Genetics 10/2010; 19(20):4072-4082. · 7.64 Impact Factor
  • Source
    Article: Functional impact of global rare copy number variation in autism spectrum disorders.
    [show abstract] [hide abstract]
    ABSTRACT: The autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in reciprocal social interaction and communication, and the presence of restricted and repetitive behaviours. Individuals with an ASD vary greatly in cognitive development, which can range from above average to intellectual disability. Although ASDs are known to be highly heritable ( approximately 90%), the underlying genetic determinants are still largely unknown. Here we analysed the genome-wide characteristics of rare (<1% frequency) copy number variation in ASD using dense genotyping arrays. When comparing 996 ASD individuals of European ancestry to 1,287 matched controls, cases were found to carry a higher global burden of rare, genic copy number variants (CNVs) (1.19 fold, P = 0.012), especially so for loci previously implicated in either ASD and/or intellectual disability (1.69 fold, P = 3.4 x 10(-4)). Among the CNVs there were numerous de novo and inherited events, sometimes in combination in a given family, implicating many novel ASD genes such as SHANK2, SYNGAP1, DLGAP2 and the X-linked DDX53-PTCHD1 locus. We also discovered an enrichment of CNVs disrupting functional gene sets involved in cellular proliferation, projection and motility, and GTPase/Ras signalling. Our results reveal many new genetic and functional targets in ASD that may lead to final connected pathways.
    Nature 07/2010; 466(7304):368-72. · 36.28 Impact Factor
  • Source
    Article: A genome-wide linkage and association scan reveals novel loci for autism
    [show abstract] [hide abstract]
    ABSTRACT: Although autism is a highly heritable neurodevelopmental disorder, attempts to identify specific susceptibility genes have thus far met with limited success
    Nature 10/2009; 461(7265):802-808. · 36.28 Impact Factor
  • Article: Fine mapping and association studies in a candidate region for autism on chromosome 2q31-q32.
    [show abstract] [hide abstract]
    ABSTRACT: Autism (OMIM %209850) is a neurodevelopmental disorder with a strong genetic component. We previously reported a de novo rearrangement of chromosome 2q31 in a patient with autism [Gallagher et al. (2003); J Autism Dev Disord 33(1):105-108]. Further cytogenetic analysis revealed this to be a 46,XY, t(9;2)(q31.1;q32.2q31.3) translocation. Association mapping with microsatellite and SNP markers of this translocated region on 2q revealed association with markers in Integrin alpha-4 (ITGA4; GeneID 3676). ITGA4 was tested for association in a sample of 179 trio-based families. SNP markers in exons 16 and 17 showed evidence of association. Mutation screening revealed a G to A synonymous variation in the last nucleotide of exon 16 (rs12690517), significantly associated with autism in the Irish sample (OR = 1.6; P = 0.04). The location of this SNP at a putative splice donor site may affect the splicing of the ITGA4 protein. Haplotype analysis showed significant overtransmission of haplotypes surrounding this marker. These markers were investigated in two additional samples, 102 families from Vanderbilt University (VT) (n = 102), and AGRE (n = 267). A non-significant trend towards overtransmission of the associated allele of rs12690517 in the Irish sample (OR = 1.2; P = 0.067) and haplotypes at the 3' end of ITGA4 was observed in the AGRE sample. The VT sample showed association with markers and haplotypes across the gene, but no association with the rs12690517 marker or its surrounding haplotypes. The combined sample showed evidence of association with rs12690517 (OR = 1.3; P = 0.008) and surrounding haplotypes. The findings indicate some evidence for the role of ITGA4 as candidate gene for autism.
    American Journal of Medical Genetics Part B Neuropsychiatric Genetics 11/2008; 150B(4):535-44. · 3.70 Impact Factor
  • Article: Fine mapping and association studies in a candidate region for autism on chromosome 2q31–q32
    [show abstract] [hide abstract]
    ABSTRACT: Autism (OMIM %209850) is a neurodevelopmental disorder with a strong genetic component. We previously reported a de novo rearrangement of chromosome 2q31 in a patient with autism [Gallagher et al. (2003); J Autism Dev Disord 33(1):105–108]. Further cytogenetic analysis revealed this to be a 46,XY, t(9;2)(q31.1;q32.2q31.3) translocation. Association mapping with microsatellite and SNP markers of this translocated region on 2q revealed association with markers in Integrin alpha-4 (ITGA4; GeneID 3676). ITGA4 was tested for association in a sample of 179 trio-based families. SNP markers in exons 16 and 17 showed evidence of association. Mutation screening revealed a G to A synonymous variation in the last nucleotide of exon 16 (rs12690517), significantly associated with autism in the Irish sample (OR = 1.6; P = 0.04). The location of this SNP at a putative splice donor site may affect the splicing of the ITGA4 protein. Haplotype analysis showed significant overtransmission of haplotypes surrounding this marker. These markers were investigated in two additional samples, 102 families from Vanderbilt University (VT) (n = 102), and AGRE (n = 267). A non-significant trend towards overtransmission of the associated allele of rs12690517 in the Irish sample (OR = 1.2; P = 0.067) and haplotypes at the 3′ end of ITGA4 was observed in the AGRE sample. The VT sample showed association with markers and haplotypes across the gene, but no association with the rs12690517 marker or its surrounding haplotypes. The combined sample showed evidence of association with rs12690517 (OR = 1.3; P = 0.008) and surrounding haplotypes. The findings indicate some evidence for the role of ITGA4 as candidate gene for autism. © 2008 Wiley-Liss, Inc.
    American Journal of Medical Genetics Part B Neuropsychiatric Genetics 10/2008; 150B(4):535 - 544. · 3.70 Impact Factor
  • Article: Evaluation of the Golgi trafficking protein VPS54 (wobbler) as a candidate for ALS.
    [show abstract] [hide abstract]
    ABSTRACT: VPS54 is a component of the Golgi-associated retrograde protein (GARP) complex of vesicle sorting proteins. A missense mutation of Vps54 is responsible for motor neuron disease in the wobbler mouse, but the human gene on chromosome 2p14-15 has not been evaluated as a disease gene. We completely sequenced the 22 coding exons from 96 individuals with sporadic ALS, 96 individuals with familial ALS, and 96 controls. Twenty-one novel SNPs were identified. The non-synonymous variant, T360A, was observed in one patient and 0/910 controls. Several polymorphic non-synonymous SNPs were also observed in patients and controls. These initial data suggest that mutations in VPS54 are not a major cause of ALS.
    Amyotrophic Lateral Sclerosis 07/2008; 9(3):141-8. · 3.40 Impact Factor
  • Article: ANG mutations segregate with familial and 'sporadic' amyotrophic lateral sclerosis.
    [show abstract] [hide abstract]
    ABSTRACT: We recently identified angiogenin (ANG) as a candidate susceptibility gene for amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder characterized by adult-onset loss of motor neurons. We now report the finding of seven missense mutations in 15 individuals, of whom four had familial ALS and 11 apparently 'sporadic' ALS. Our findings provide further evidence that variations in hypoxia-inducible genes have an important role in motor neuron degeneration.
    Nature Genetics 05/2006; 38(4):411-3. · 35.53 Impact Factor
  • Article: Uroplakin III is not a major candidate gene for primary vesicoureteral reflux.
    [show abstract] [hide abstract]
    ABSTRACT: Vesicoureteral reflux (VUR) is the retrograde flow of urine from the bladder into the ureter and towards the kidneys. VUR is the most common cause of end stage renal failure in both children and adults and it is a major cause of severe hypertension in children. VUR is seen in approximately 1-2% of newborn Caucasians. Substantial evidence exists that VUR is a genetic disorder. Uroplakins are integral membrane proteins found in the bladder wall. Knockout studies in mice have suggested uroplakin III (UPK3) as a candidate gene for VUR. We have used parametric and nonparametric linkage analysis and tests for association, to investigate this possibility in a cohort of 126 sibling pairs affected with primary VUR. None of the analyses showed any substantial evidence for linkage or association of markers at the UPK3 locus to VUR. Our results do not support a role for UPK3 in primary VUR.
    European Journal of HumanGenetics 05/2005; 13(4):500-2. · 4.40 Impact Factor
  • Article: Tumor necrosis factor-alpha gene polymorphism in reflux nephropathy.
    [show abstract] [hide abstract]
    ABSTRACT: Interstitial scarring contributes to the progression of renal failure in reflux nephropathy. The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) has been implicated in the disease susceptibility and pathogenesis of several inflammatory diseases promoting interstitial infiltration of inflammatory cells. We evaluate the frequency of TNF-alpha gene polymorphism in patients with reflux nephropathy. Renal scarring was evaluated with technetium dimercapto-succinic acid renal scan. Genotyping was performed on 104 patients with reflux nephropathy and 30 controls for the TNF-alpha gene polymorphisms using polymerase chain reaction and restriction digest. This polymorphism involved a guanidine to adenosine transition at position -308 and was designated as TNF1 (-308G) and TNF2 (-308A). The allele frequencies of TNF1 and TNF2 were 18.8% and 81.2% in patients with reflux nephropathy and 76.7% and 23.3% in controls, respectively. The genotype distribution of TNF-alpha-AA was significantly higher (66.4% vs 10%, p <0.05), while the TNF-alpha-GG was lower (13.4% vs 60%, p <0.05) in patients with reflux nephropathy compared to controls. This study demonstrates for the first time the association of the cytokine TNF-alpha gene polymorphism in patients with reflux nephropathy. Our data suggest that patients with vesicoureteral reflux and TNF-alpha AA genotype may have increased susceptibility to reflux nephropathy.
    The Journal of Urology 10/2004; 172(4 Pt 2):1604-6; discussion 1606. · 3.75 Impact Factor
  • Article: TUMOR NECROSIS FACTOR-α GENE POLYMORPHISM IN REFLUX NEPHROPATHY
    [show abstract] [hide abstract]
    ABSTRACT: Purpose:Interstitial scarring contributes to the progression of renal failure in reflux nephropathy. The proinflammatory cytokine tumor necrosis factor-α (TNF-α) has been implicated in the disease susceptibility and pathogenesis of several inflammatory diseases promoting interstitial infiltration of inflammatory cells. We evaluate the frequency of TNF-α gene polymorphism in patients with reflux nephropathy.Material and Methods:Renal scaring was evaluated with 99technetium dimercapto-succinic acid renal scan. Genotyping was performed on 104 patients with reflux nephropathy and 30 controls for the TNF-α gene polymorphisms using polymerase chain reaction and restriction digest. This polymorphism involved a guanidine to adenosine transition at position −308 and was designated as TNF1 (−308G) and TNF2 (−308A).Results:The allele frequencies of TNF1 and TNF2 were 18.8% and 81.2% in patients with reflux nephropathy and 76.7% and 23.3% in controls, respectively. The genotype distribution of TNF-α-AA was significantly higher (66.4% vs 10%, p <0.05), while the TNF-α-GG was lower (13.4% vs 60%, p <0.05) in patients with reflux nephropathy compared to controls.Conclusions:This study demonstrates for the first time the association of the cytokine TNF-α gene polymorphism in patients with reflux nephropathy. Our data suggest that patients with vesicoureteral reflux and TNF-α AA genotype may have increased susceptibility to reflux nephropathy.
    The Journal of Urology.