PubMed Health⌕ Search

Biomedical subjects

M Devoto

Publications and source records attributed to M Devoto.

At least 19 recordsLinked to original sources

Variants of OCTN1-2 cation transporter genes are associated with both Crohn's disease and ulcerative colitis.

BACKGROUND: Two variants in the organic cation transporter gene cluster have been recently reported to confer susceptibility to Crohn's disease (CD). AIM: To investigate these variants in CD and ulcerative colitis (UC), and their interaction with CARD15 gene and correlation to clinical subphenotypes. METHODS: Case-control association analysis was performed in 899 patients (444 CD and 455 UC) and 611 controls. The organic cation transporter gene cluster single nucleotide polymorphisms G207G-->C and 1672C-->T, the IGR2198a_1 single nucleotide polymorphism in the IBD5 locus, and the R702W, G908R and L1007finsC variants of CARD15 gene were genotyped by ABI-7700, restriction fragment length polymorphic analysis and multiplex pyrosequencing, respectively. RESULTS: The 1672TT and -207CC genotype frequencies were increased in both CD (OR = 1.5, P = 0.011; OR = 1.6, P = 0.002), and UC (OR = 1.5, P = 0.017; OR = 1.4, P = 0.033), respectively. Compared with controls, the TC haplotype frequency was increased in both CD (36% vs. 44%, P < or = 0.01) and UC (36% vs. 45%, P < or = 0.01). The frequency of the TC haplotype was 43% in CARD15-positive and 44% in CARD15-negative CD, respectively. Similar results were found in UC. In CD a significant association of the TC haplotype was found with presence of perianal fistulae (P = 0.007) and steno-fistulizing behaviour (P = 0.037). In UC, the TC haplotype was more frequent in patients with more extensive disease (P = 0.015), and those on immunosuppressives (P = 0.004). CONCLUSIONS: Organic cation transporter gene cluster variants may confer susceptibility to both CD and UC, and the TC haplotype may influence some clinical features of IBD, but does not interact with CARD15 variants.

Adult↗

Haplotypes of the human RET proto-oncogene associated with Hirschsprung disease in the Italian population derive from a single ancestral combination of alleles.

The RET proto-oncogene is the major gene involved in the complex genetics of Hirschsprung disease (HSCR), or aganglionic megacolon, showing causative loss-of-function mutations in 15-30% of the sporadic cases. Several RET polymorphisms and haplotypes have been described in association with the disease, suggesting a role for this gene in HSCR predisposition, also in the absence of mutations in the coding region. Finally, the presence of a functional variant in intron 1 has repeatedly been proposed to explain such findings. Here we report a case-control study conducted on 97 Italian HSCR sporadic patients and 85 population matched controls, using 13 RET polymorphisms distributed throughout the gene, from the basal promoter to the 3'UTR. Linkage disequilibrium and haplotype analyses have shown increased recombination between the 5' and 3' portions of the gene and an over-representation, in the cases studied, of two haplotypes sharing a common allelic combination that extends from the promoter up to intron 5. We propose that these two disease-associated haplotypes derive from a single founding locus, extending up to intron 19 and successively rearranged in correspondence with a high recombination rate region located between the proximal and distal portions of the gene. Our results suggests the possibility that a common HSCR predisposing variant, in linkage disequilibrium with such haplotypes, is located further downstream than the previously suggested interval encompassing intron 1.

Alleles↗

Multidrug resistance 1 gene polymorphisms are not associated with inflammatory bowel disease and response to therapy in Italian patients.

BACKGROUND: Host genetic factors may be important in determining not only disease susceptibility, but also disease behaviour and response to therapy in inflammatory bowel disease. Two polymorphisms (C3435T and G2677T/A) of the multidrug resistance 1 gene have been correlated with the altered P-glycoprotein expression and function in humans, and associated with predisposition to ulcerative colitis and Crohn's disease. AIM: To investigate the contribution of these polymorphisms to disease susceptibility and response to medical therapy. METHODS: A total of 946 inflammatory bowel disease patients (478 Crohn's disease, 272 males, mean age 43 +/- 14 years and 468 ulcerative colitis, 290 males, mean age 48 +/- 15 years) and 450 healthy controls were genotyped for the single nucleotide polymorphisms C3435T and G2677T/A. Patients were also classified on the basis of response to medical therapy (mesalazine, steroids, immunosuppressives and infliximab). RESULTS: Both single nucleotide polymorphisms were in Hardy-Weinberg equilibrium and significant linkage disequilibrium. No significant difference in the allele, genotype, and haplotype frequencies was found in both Crohn's disease and ulcerative colitis patients compared with the controls. No correlation with clinical features was found, except for a reduced frequency of extra-intestinal manifestations in Crohn's disease patients with the G2677T genotype (40%) compared with GG2677 and 2677TT genotypes (54% and 58%, respectively) (P = <0.02). No significant difference was also found after stratifying the patients on the basis of their response to medical therapy. CONCLUSION: The investigated polymorphisms of the multidrug resistance 1 gene have no significant role in disease susceptibility and response to medical therapy in our Italian population of inflammatory bowel disease patients.

Case-Control Studies↗

Association of T-786C eNOS gene polymorphism with increased susceptibility to acute chest syndrome in females with sickle cell disease.

Acute chest syndrome (ACS) is a life-threatening complication of sickle cell disease (SCD). A retrospective study was performed to evaluate the role of endothelial nitric oxide synthase (eNOS) gene polymorphisms (E298D and T-786C) in African-American SCD patients. The D298 allele showed no association; the C-786 allele showed a statistically significant association (P = 0.0061) in female ACS cases. Multiple logistic regression analysis showed that relative risk of ACS was 8.695 (P = 0.0076, 95% confidence interval 1.761-42.920) for female carriers of C-786. eNOS T-786C is a gender-specific genetic modifier that is associated with increased susceptibility to ACS in female SCD patients.

Acute Disease↗

Association analysis of bone mineral density and single nucleotide polymorphisms in two candidate genes on chromosome 1p36.

Two candidate genes for bone mineral density (BMD), tumor necrosis factor alpha receptor 2 (TNFRSF1B) and lysyl hydroxylase (PLOD1), have been scanned for single nucleotide polymorphisms (SNPs) within their coding and promoter regions. These two genes, separated by about 200 kb, are located within the chromosomal interval 1p36.2-1p36.3 that has been linked to femoral neck BMD. In a patient population (n = 104) of European descent, there were four SNPs within TNFRSF1B and six SNPs within PLOD1 that occurred with greater than 5% frequency. There was significant linkage disequilibrium within both genes. Single marker analysis revealed significant association for one SNP located in intron 6 of PLOD1 and lumbar spine BMD (P = 0.01). Allelic haplotypes that encompassed the four SNPs in TNFRSF1B or the six SNPs in PLOD1 were assigned using a Bayesian algorithm as implemented in the program Haplotyper. Association of TNFRSF1B haplotypes with femoral neck BMD was statistically significant (P = 0.01). Similarly, PLOD1 haplotypes demonstrated a statistically significant association with spinal BMD (P = 0.04). These findings strengthen the potential importance of chromosome 1p36.2-1p36.3 in contributing to BMD variation, and are consistent with genetic variation in either PLOD1, TNFRSF1B or nearby genes playing a role in the phenotype.

Antigens, CD↗

Variance component linkage analysis indicates a QTL for femoral neck bone mineral density on chromosome 1p36.

Osteoporosis is a common condition characterized by reduced skeletal strength and increased susceptibility to fracture. Eight million Americans over the age of 50 have osteoporosis of the femoral neck. The most important risk factor for osteoporosis is low bone mineral density (BMD), and several epidemiological studies have shown the importance of genetic factors in determining variability of BMD. An initial genome screen in seven large pedigrees suggested that a candidate region conferring susceptibility to low BMD of the femoral neck was located on chromosome 1p36. We have now confirmed and extended this finding by analyzing nine microsatellite markers spanning a 40 cM interval across the candidate region in an expanded sample of 42 families. Heritability of femoral neck BMD was estimated as 0.51 +/- 0.13 in these families, after accounting for the effects of age, sex, body mass index, height and weight. Variance component linkage analysis yielded a maximum multipoint LOD score of 3.53 for linkage of femoral neck BMD to a quantitative trait locus (QTL) located near marker D1S214. The associated empirical P-value by simulation analysis was equal to 0.0001. The results strongly support the hypothesis that a major QTL controlling femoral neck BMD is located on chromosome 1p36.2-p36.3, and further analysis of candidate genes in this region is warranted.

Adolescent↗

Novel X-linked mental retardation syndrome with short stature maps to Xq24.

We describe a large family from Sardinia, Italy, in which a novel X- linked mental retardation (XLMR) syndrome segregates. The phenotype observed in the 8 affected males includes severe mental retardation (MR), lack of speech, coarse face, distinctive skeletal features with short stature, brachydactyly of fingers and toes, small downslanting palpebral fissures, large bulbous nose, hypoplastic ear lobe and macrostomia. Carrier females are not mentally retarded, although some of them have mild dysmorphic features such as minor ear lobe abnormalities, as well as language and learning problems. Linkage analysis for X-chromosome markers resulted in a maximum lod score of 3.61 with marker DXS1001 in Xq24. Recombination observed with flanking markers identified a region of 16 cM for further study. None of the other XLMR syndromes known to map in the same region shows the same composite phenotype. This evidence strongly suggests that the genetic disease in this family is unique.

Adolescent↗

Exclusion of linkage to the CDL1 gene region on chromosome 3q26.3 in some familial cases of Cornelia de Lange syndrome.

Cornelia de Lange Syndrome (CdLS) is a complex developmental disorder consisting of characteristic facial features, limb abnormalities, hirsutism, ophthalmologic involvement, gastroesophageal dysfunction, hearing loss, as well as growth and neurodevelopmental retardation. Most cases of CdLS appear to be sporadic. Familial cases are rare and indicate autosomal dominant inheritance. Several individuals with CdLS have been reported with chromosomal abnormalities, suggesting candidate genomic regions within which the causative gene(s) may lie. A CdLS gene location (CDL1) has been assigned to 3q26.3 based on phenotypic overlap with the duplication 3q syndrome (critical region 3q26.2-q27) and the report of a CdLS individual with a balanced de novo t(3;17)(q26.3;q23.1). It has been postulated that a gene within the dup3q critical region results in the CdLS when deleted or mutated. We have performed a linkage analysis to the minimal critical region for the dup3q syndrome (that encompasses the translocation breakpoint) on chromosome 3q in 10 rare familial cases of CdLS. Nineteen markers spanning a region of approximately 40 Mb (37 cM) were used. Results of a multipoint linkage analysis demonstrated total lod-scores that were negative across the chromosome 3q26-q27 region. In 4/10 families, lod-scores were less than -2 in the 2 cM region encompassing the translocation, while in the remaining 6/10 families, lod-scores could not exclude linkage to this region. These studies indicate that in some multicase families, the disease gene does not map to the CDL1 region at 3q26.3.

Chromosomes, Human, Pair 3↗

Comparison of sib pair-based approaches for identifying quantitative trait loci underlying asthma in the Busselton families.

The goal of this study is to determine the linkage relationship between IgE levels and the 269 microsatellite markers using the Genetic Analysis Workshop 12 Busselton data set. Analyses were carried out using both traditional and new Haseman-Elston methods, the maximum likelihood quantitative trait locus estimation (MLE QTL) method and the nonparametric (NP QTL) method. Our analyses confirmed some of the signals reported by Daniels et al. [Nature 383:247-50, 1996]. We also observed that several significant signals reported in the original report became insignificant (D6S76 and D11S96) and several new signals showed up after the data were reanalyzed using the new Haseman-Elston method, the MLE QTL method, and the NP QTL method. Based on the original and the current analyses, we recommend that follow-up studies of three regions including D7S2250, FCER1B, D11S901, and six markers on chromosome 16 be given higher priority.

Adult↗

Exclusion of candidate genes and chromosomal regions in familial neuroblastoma.

Two families with recurrence of neuroblastoma one Italian and one British with three and two affected children respectively were genotyped using polymorphic markers on chromosome 1 spanning the p32-p36 region frequently deleted in neuroblastoma tumor cells. Linkage to this region was excluded by haplotype inspection and negative lod scores. Furthermore, the exclusion of genes involved in neurocristopathies sometimes associated with neuroblastoma was carried out by typing the Italian family with polymorphic markers located in or near the corresponding genes. Finally, linkage analysis in the two families showed negative lod scores for markers spanning the 16p12-13 chromosomal region where a locus for familial neuroblastoma has been recently mapped. Our findings indicate that different genes are involved in the pathogenesis of familial neuroblastoma.

Chromosome Mapping↗

Genetic refinement and physical mapping of the CMT4B gene on chromosome 11q22.

Charcot-Marie-Tooth disease type 4B (CMT4B) is a demyelinating autosomal recessive motor and sensory neuropathy characterized by focally folded myelin sheaths in the peripheral nerve. We recently mapped the CMT4B gene to a 5-cM interval on chromosome 11q22, using homozygosity mapping and haplotype sharing analysis on a large inbred pedigree. In the present study, we report the construction of a YAC-based transcript map across the 5-cM critical region, including 26 YACs, 35 STSs, and 52 ESTs. Furthermore, using 15 additional physically ordered microsatellite markers from the 11q22 region on the original inbred family, we were able to narrow the critical interval for the gene to 2 Mb, which is now flanked by markers D11S1757 and CHLC-GATA3B05. Finally, after computer analysis of the 33 ESTs assigned to the 2-Mb interval, we demonstrated that 21 different transcripts as well as 3 known genes might represent potential candidates for the disease.

Charcot-Marie-Tooth Disease↗

Charcot-Marie-Tooth type 4B is caused by mutations in the gene encoding myotubularin-related protein-2.

A gene mutated in Charcot-Marie-Tooth disease type 4B (CMT4B), an autosomal recessive demyelinating neuropathy with myelin outfoldings, has been mapped on chromosome 11q22. Using a positional-cloning strategy, we identified in unrelated CMT4B patients mutations occurring in the gene MTMR2, encoding myotubularin-related protein-2, a dual specificity phosphatase (DSP).

Alternative Splicing↗

A single-nucleotide polymorphic variant of the RET proto-oncogene is underrepresented in sporadic Hirschsprung disease.

Hirschsprung disease (HSCR) is an inherited disorder characterised by absence of intrinsic ganglion cells in the distal gastrointestinal tract. Different susceptibility genes, involved in either the Ret-tyrosine kinase or the endothelin signalling pathways, contribute to HSCR phenotype. Interestingly, alterations of these genes are detected in only 30-50% of all HSCR patients, suggesting the involvement of modifier genes and/or additional genetic or environmental risk factors. In complex disorders common polymorphic variants can be associated with the disease phenotype, thus modifying the risk of recurrence. To investigate whether sequence variants of the RET proto-oncogene may be associated with the development of the HSCR phenotype, we analysed 92 Italian patients for the 2508C > T synonymous substitution in exon 14 (S836S) finding that the T allele is clearly less frequent than in control individuals (Fisher exact test P = 0.0002). On the other hand, this RET variant allele is overrepresented in patients affected with medullary thyroid carcinoma. Assuming a direct effect of this single-nucleotide polymorphism in predisposing to RET associated pathologies, we have performed functional tests which excluded any possible involvement of the C and T alleles in DNA-protein binding, transcript stability and RNA splicing and editing.

Alleles↗