Association between SNAP-25 gene polymorphisms and cognition in autism: functional consequences and potential therapeutic strategies.

Synaptosomal-associated protein of 25 kDa (SNAP-25) is involved in different neuropsychiatric disorders, including schizophrenia and attention-deficit/hyperactivity disorder. Consistently, SNAP-25 polymorphisms in humans are associated with hyperactivity and/or with low cognitive scores. We analysed five SNAP-25 gene polymorphisms (rs363050, rs363039, rs363043, rs3746544 and rs1051312) in 46 autistic children trying to correlate them with Childhood Autism Rating Scale and electroencephalogram (EEG) abnormalities. The functional effects of rs363050 single-nucleotide polymorphism (SNP) on the gene transcriptional activity, by means of the luciferase reporter gene, were evaluated. To investigate the functional consequences that SNAP-25 reduction may have in children, the behaviour and EEG of SNAP-25(+/-) adolescent mice (SNAP-25(+/+)) were studied. Significant association of SNAP-25 polymorphism with decreasing cognitive scores was observed. Analysis of transcriptional activity revealed that SNP rs363050 encompasses a regulatory element, leading to protein expression decrease. Reduction of SNAP-25 levels in adolescent mice was associated with hyperactivity, cognitive and social impairment and an abnormal EEG, characterized by the occurrence of frequent spikes. Both EEG abnormalities and behavioural deficits were rescued by repeated exposure for 21 days to sodium salt valproate (VLP). A partial recovery of SNAP-25 expression content in SNAP-25(+/-) hippocampi was also observed by means of western blotting. A reduced expression of SNAP-25 is responsible for the cognitive deficits in children affected by autism spectrum disorders, as presumably occurring in the presence of rs363050(G) allele, and for behavioural and EEG alterations in adolescent mice. VLP treatment could result in novel therapeutic strategies.

Looking at my body. Similarities and differences between anorexia nervosa patients and controls in body image visual processing.

BACKGROUND: Body image distortion is a core symptom of eating disorders. Functional magnetic resonance imaging (fMRI) studies on body image processing, described different patterns of neural response, mainly involving the inferior and superior parietal lobules, and the dorsolateral prefrontal cortex (DLPFC), with conflicting results. METHODS: The neural response to the view of their own body pictures (normal size and distorted) was evaluated in 18 female anorexia nervosa (AN) restricting type patients, and in 19 healthy female subjects (HC) using fMRI. Clinical assessment was performed by means of the structured clinical interview for DSM-IV and self-reported questionnaires. RESULTS: In response to the body image distortion, patients and controls showed an inverse pattern of activation, with the widest extent of activation in the oversize condition in AN, while in the undersize condition in HC. AN and HC showed a similar pattern of neural response to the view of their own body, with an increased activation in the extrastriate body area, superior and inferior parietal lobule and prefrontal areas, although the extent of activation in HC was more limited as compared with AN patients. Increased activity in AN patients, compared with HC, was observed in the DLPFC in response to the oversized body picture and a significant correlation was found in AN patients between DLPFC activation and eating disorder psychopathology. CONCLUSIONS: Our findings suggest the existence of a continuum from normalcy to pathology in neural response to body image, and confirm the clinical relevance of body image distortion in AN, reinforcing the key role of attentive, executive and self-evaluation networks in AN visual processing of own distorted body image.

HLA-class I markers and multiple sclerosis susceptibility in the Italian population.

Previous studies reported an association with multiple sclerosis (MS) of distinct HLA-class I markers, namely HLA-A*02, HLA-Cw*05 and MOG-142L. In this work, we tested the association with MS of A*02 and Cw*05 in 1273 Italian MS patients and 1075 matched controls, which were previously analyzed for MOG-142, and explored the relationship among these three markers in modulating MS risk. HLA-A*02 conferred a statistically robust MS protection (odds ratio, OR=0.61; 95% confidence intervals, CI=0.51-0.72, P<10(-9)), which was independent of DRB1*15 and of any other DRB1* allele and remained similar after accounting for the other two analyzed class I markers. Conversely, the protective effect we previously observed for MOG-142L was secondary to its linkage disequilibrium with A*02. Cw*05 was not associated considering the whole sample, but its presence significantly enhanced the protection in the HLA-A*02-positive group, independently of DRB1: the OR conferred by A*02 in Cw*05-positive individuals (0.22, 95% CI=0.13-0.38) was significantly lower than in Cw*05-negative individuals (0.69, 95% CI=0.58-0.83) with a significant (P=4.94 x 10(-5)) multiplicative interaction between the two markers. In the absence of A*02, Cw*05 behaved as a risk factor, particularly in combination with DRB1*03 (OR=3.89, P=0.0006), indicating that Cw*05 might be a marker of protective or risk haplotypes, respectively.

A sequence variation in the MOG gene is involved in multiple sclerosis susceptibility in Italy.

Several studies suggest that the histocompatibility complex (HLA) class I region harbours genes modulating multiple sclerosis (MS) susceptibility independently from the effect of class II alleles. A candidate gene in this region is MOG, encoding the myelin oligodendrocyte glycoprotein. A significant association with the missense variation V142L (rs2857766) was previously reported in a small sample of 50 Italian MS patients. We confirmed this result in two independent Italian sample sets consisting of 878 MS patients and 890 matched controls (P=6.6 x 10(-4)) and 246 trio families (P=1.5 x 10(-3)). The comparison of genotype frequencies suggested a dominant-protective effect of L142. In the combined sample sets L142 conferred an odds ratio (OR)=0.70 (95% confidence interval (CI): 0.60-0.82) that remained similar after accounting for HLA-DRB1(*)15 carrier status. The association with MOG V142L was still significant after conditioning for all DRB1 alleles (P=0.035). Eleven additional single nucleotide polymorphisms in the MOG gene (namely -1077T/C, -910T/C, -875A/G, -93T/C, S5S, Indel L22, V145I, +814C/T, +900A/G, +1024A/T, +1059C/T), two microsatellites in the MOG 5' flanking (MOGCA) and 3' untranslated (MOGTAAA) regions and four microsatellites in the HLA-class I region, from HLA-B to HFE, (namely MIB, D6S265, D6S1683 and D6S2239) were tested by transmission disequilibrium test in 199 trio families. None of these polymorphisms or of their haplotypic combinations showed a significant transmission distortion, in the absence of V142L. In conclusion, MOG V142L, or an untested variant in tight-linkage disequilibrium with it, is an independent MS susceptibility-modulating factor in the HLA class I region.

A family-based study does not confirm the association of MYO9B with celiac disease in the Italian population.

Association between Myosin IXB (MYO9B) gene polymorphisms and celiac disease (CD) was recently detected by a case-control association study in the Dutch, but not confirmed in the British and Swedish/Norwegian populations. We tested the association between CD and the three most associated single nucleotide polymorphisms (SNPs) in the Dutch study by the transmission disequilibrium test in the Italian population. A total of 252 pediatric patients and 504 parents were genotyped. No transmission distortion was detected either for the single SNPs or for their haplotypic combinations. Control allele frequencies, calculated from untransmitted alleles, were significantly different from those of the Dutch control population. Conversely, allele frequencies were very similar in Italian, British, Swedish/Norwegian and Dutch patients. In conclusion, MYO9B is not involved in CD susceptibility in the Italian population. The difference with the Dutch result might be explained by an imperfect selection of the Dutch controls.

Additional factor in some HLA DR3/DQ2 haplotypes confers a fourfold increased genetic risk of celiac disease.

Although HLA-DQ genes are the major celiac disease (CD) susceptibility genes, results from Finnish families suggest that not all DQ2-encoding haplotypes confer equal susceptibility to CD, implying the effect of other gene(s) in the HLA region. The aim of the present work was to extend and confirm the aforementioned results in a southern European population ( Italian) and to better localize the additional risk factor/s. The association of nine loci spanning the HLA region from DR to HFE, 4.5-Mb telomeric of HLA-A, was tested. The analysis was performed by comparing marker frequencies in DR3-DQ2 haplotypes transmitted and non-transmitted to the affected offspring in 156 Italian CD families selected for having at least one DR3-positive parent. The same analysis was performed independently in 101 Finnish CD families selected with the same criteria. Three alleles, MICA-A5.1, MICB-CA24 and MIB-350, all characteristic of the B8-DR3 extended haplotype, showed a significantly increased frequency in DR3 transmitted haplotypes in the Italian families. DR3 haplotypes carrying the combination of these alleles conferred an approximate fourfold increased CD risk. B8-DR3 transmitted haplotypes were significantly more conserved telomerically down to the MIC-Class I region. Similar results were seen in the Finnish families. The major conclusion that holds true in both populations is that, while DQ2 is an absolute requirement for the development of CD, the presence of an additional genetic factor within the MIC-Class I region confers an approximate 4-fold increased risk of the disease.

MICA and MICB microsatellite alleles in HLA extended haplotypes.

The present study is a contribution to the definition of the linkage disequilibrium relationship of MICA and MICB with adjacent loci and to the characterization of extended HLA haplotypes. These issues are of importance for the identification of disease associations and for a better definition of donor-recipient compatibility in bone-marrow grafts through the typing of haplospecific markers. The distribution of the five alleles of MICA and the 13 alleles of MICB microsatellites, located, respectively, in MICA transmembrane exon 5 and in MICB intron 1, was examined in 133 healthy Italian individuals previously typed for HLA class I, class II and complement loci and for the TNFa microsatellite. The MICB microsatellite was also analysed in 49 HTCLs for which MICA typing was already available. Very strong linkage disequilibria with HLA-B and TNFa were detected in the Italian population for both MICA and MICB microsatellite alleles, in spite of the high mutability rate of the larger MICB alleles. Some strong associations were also detected between MICB and DRB1. The strongest associations (P < 0.001, D' > 0.7) were those of MICA-A4 with HLA-B18, B27 and TNFa1, MICA-A5 with HLA-B35, B61 and B62, MICA-A5.1 with HLA-B7, B8, B13, B63 and MICB-CA24, MICA-A6 with HLA-B51, MICA-A9 with HLA-B39, B57 and TNFa2, MICB-CA14 with HLA-B14, B27 and TNFa1, MICB-CA15 with HLA-B52, TNFa4 and TNFa13, MICB-CA17 with HLA-B7 and TNFa11, MICB-CA18 with HLA-B13 and TNFa7, MICB-CA22 with HLA-B57, and MICB-CA24 with HLA-B8 and TNFa2. From pairwise associations in the random panel and results for the homozygous cell lines it was possible to deduce the MICA and MICB microsatellite alleles present in many of the well-known Caucasoid extended haplotypes.

HLA class I in acute promyelocytic leukemia (APL): possible correlation with clinical outcome.

The majority of patients with acute promyelocytic leukemia (APL) possess either a bcr1 or a bcr3 type fusion between PML and RARalpha genes. The junction sequences may possibly be a target for immune response and influence susceptibility to the disease. In this case, HLA class I allele frequencies would be different between bcr1 and bcr3 patients. To test this hypothesis, we typed 102 APL patients for HLA-A, -B and -Cw alleles. The A*1, A*30, B*51, B*41, Cw*0602, and Cw*1701 alleles showed a different distribution between bcr1 and bcr3 patients, but in no case was this statistically significant after correction for the number of comparisons or was confirmed in an independent panel. Moreover, no difference was detected between bcr1 and bcr3 when HLA alleles were grouped according to their peptide binding specificities. Comparing HLA frequencies, clinical features at diagnosis and clinical outcome of the 64 patients homogeneously treated with all-trans retinoic acid and idarubicin (AIDA protocol) we observed a statistically significant association between HLA-B*13 and risk of relapse by univariate and multivariate regression analysis. Should this finding be confirmed in larger future studies, this observation would be of outmost importance in identifying patients at high risk of relapse in which more aggressive consolidation therapies should be used.

Association study of a new polymorphism in the PECAM-1 gene in multiple sclerosis.

Genetic polymorphisms of immunorelevant genes may modulate occurrence or clinical features of multifactorial diseases. PECAM-1 is an adhesion molecule crucial for transmigration of cells from blood to tissues, but its genetic contribution to multifactorial diseases has never been investigated. We have identified and characterized a tetranucleotide repeat polymorphism within the third intron of PECAM-1. In a cohort of healthy controls (HC), we found 10 alleles. An assessment of the association of this polymorphism with multiple sclerosis (MS) showed similar allele and genotype frequencies in HC and MS patients as well as in MS patients differing for the gravity of their disease course. We conclude that although potentially able to affect organ-specific autoimmune diseases, this new PECAM-1 polymorphism, does not seem to contribute to the genetic background of MS.

Historical recombinant sites in extended HLA haplotypes.

Each ancestral or extended HLA haplotype contains a unique combination of alleles among which some may be entirely specific for that haplotype (haplospecific alleles). In the course of evolution many recombination events occurred which disrupted the original haplotypic combination. We analysed the sites of historical recombinations in four extended HLA haplotypes (B8-DR3; B18-DR3; B50-DR7 and B57-DR7) in 60 random Italian individuals selected through the presence of haplospecific alleles. In general the distribution of recombinations in each interval was similar for the four extended haplotypes and no haplospecific recombination "hot spot" could be detected. However some differences between the four haplotypes can be pointed out: a) only 48% fragmented B8-DR3 were found in contrast to 83% B18-DR3, 89% B50-DR7 and 88% B57-DR7; b) in the B8-DR3 haplotype recombinations fall preferentially in the B/TNF interval. In fact among 22 historical recombination events, 50% were mapped in this region; c) conversely, no recombination event was detected in the B/TNF interval among the 19 disrupted B18-DR3 haplotypes thus evidencing the presence of a putative recombination "cold spot".

Linkage disequilibrium between intra-locus variants in the aminopeptidase n gene and test of their association with coeliac disease.

Coeliac disease (CD) is a multigenic and multifactorial enteropathy triggered by gluten-composing proteins. A possible involvement of the intestinal Aminopeptidase N (APN) was investigated by an association analysis. SSCP analysis detected four variants at position 281, 378, 956 and 2957 (referred to no. g178535, GenBank) that were studied in 193 Italian CD families. The haplotypic combinations were determined from family segregation and pairwise linkage disequilibria (D' = D/Dmax) between the polymorphic sites were calculated. Significant D' values ranged between 0.78 and 0.31. Association with CD was tested by TDT (Transmission Disequilibrium Test) utilizing as markers the nucleotide substitutions and their haplotypic combinations. No statistically significant transmission distortion to the probands or to their clinically silent sibs was observed. Our data exclude an involvement in CD of the tested markers and of further undetected variation in strong linkage disequilibrium (D' approximately equal to 1) with them. The power of the test was not adequate to detect an association with an unknown polymorphism which is not in complete linkage disequilibrium with those analysed.

The natural history of an HLA haplotype and its recombinants.

The presence of haplotype-specific recombination sites can be determined by analyzing the conservation of extended haplotypes in the population. This approach considers all meioses in the history of the population and requires the presence of characteristic markers that easily allow the identification of the haplotype or of its recombined segments. The recombination breakpoint can then be mapped by looking for shared alleles between haplotypes selected through the specific marker/s. We identified a rare perfect tandem duplication of a 145 base pair segment in the LTA promoter, which tags a B60 (B60D) haplotype. The duplication was detected in 16/90 B60+ Europeans, while absent in 101 B60+ Orientals. The conservation of the class I end and the extreme variability of the class II end suggested that the present-day B60D haplotypes originated from an ancestral haplotype by recombination events centromeric to the duplicated sequence. Through a fine mapping using markers of the HLA central region a preferential recombination site was localized in the 60 kilobase interval between TNFd,e, and D6S273/K11 Amicrosatellite loci (i.e., between LST1 and BAT3 genes). This site behaves as a potent recombination enhancer leading to fragmentation in most of the extant B60D haplotypes and can be considered responsible for their "instability". In the relatively recently founded Finnish population, where the LST1/BAT3 interval recombination has probably not yet had the chance to occur, a founder effect can explain the presence of a rare DP (DPB1(*)1601) allele in most B60D haplotypes in this population.

Psychological, behavioral and biochemical risk factors for coronary artery disease among American and Italian male corporate managers.

Differences in psychological, behavioral and biochemical risk factors for coronary artery disease (CAD) among male corporate managers of 2 countries (United States and Italy), with very different age-specific rates of mortality for CAD were evaluated. In all, 129 American (mean age 43 +/- 7 years) and 80 Italian (mean age 45 +/- 7 years) managers volunteered to participate in this study. Each subject was administered several questionnaires assessing various psychological and behavioral risk factors for CAD, and all 129 Americans and 55 of 80 Italians had their blood drawn between 8:00 and 9:30 AM after overnight fasting for the measurement of plasma levels of dehydroepiandrosterone-sulfate (DHEA-S), total cholesterol, triglycerides, and apolipoproteins A-I and B. Italian managers reported significantly more cynicism and hostility, and less enjoyment in leisure activities than did American ones. Furthermore, 40 Italian (51%) and only 18 American (14%) managers were smokers (this difference being statistically significant). Although no significant differences were found in factors positively related with CAD (cholesterol, triglycerides and apolipoprotein B), there were clear differences in parameters inversely correlated with the incidence of CAD. Italian managers had significantly lower levels of plasma DHEA-S and apolipoprotein A-I than did American ones. In conclusion, this study found that Italian managers had a significantly more unhealthy psychological and behavioral profile than did American ones, and had lower levels of those biochemical parameters (apolipoprotein A-I and DHEA-S) thought to have a protective role against development of CAD.