Long-term cognitive trajectories and heterogeneity in patients with schizophrenia and their unaffected siblings.

OBJECTIVE: This study aimed to assess the heterogeneity and stability of cognition in patients with a non-affective psychotic disorder and their unaffected siblings. In addition, we aimed to predict the cognitive subtypes of siblings by their probands. METHOD: Assessments were conducted at baseline, 3 and 6 years in 1119 patients, 1059 siblings and 586 controls from the Genetic Risk and Outcome of Psychosis (GROUP) study. Group-based trajectory modeling was applied to identify trajectories and clustered multinomial logistic regression analysis was used for prediction modeling. A composite score of eight neurocognitive tests was used to measure cognitive performance. RESULTS: Five stable cognitive trajectories ranging from severely altered to high cognitive performance were identified in patients. Likewise, four stable trajectories ranging from moderately altered to high performance were found in siblings. Siblings had a higher risk of cognitive alteration when patients' alteration was mild (OR = 2.21), moderate (OR = 5.70), and severe (OR = 10.07) compared with patients with intact cognitive function. The familial correlation coefficient between pairs of index patients and their siblings was 0.27 (P = 0.003). CONCLUSIONS: The cognitive profiles identified in the current study might be suitable as endophenotypes and could be used in future genetic studies and predicting functional and clinical outcomes.

IL6R haplotype rs4845625*T/rs4537545*C is a risk factor for simultaneously high CRP, LDL and ApoB levels.

Interleukin 6 receptor (IL-6R), mediating IL-6's biological functions, plays an important role in different diseases such as diabetes, obesity and cardio-vascular diseases. In this study, we investigated the effects of two single nucleotide polymorphisms (SNPs), within the IL-6R loci, previously associated with C-reactive protein (CRP) and coronary heart diseases risk, and with controversial effects on lipids traits: SNP rs4845625 and SNP rs4537545. The results showed that both investigated SNPs were antagonistically related with CRP levels; the minor rs4845625*T allele was associated with increased CRP levels (P-value=0.011), while the minor rs4537545*T allele was associated with decreased CRP levels (P-value=0.009). Interestingly, the minor rs4845625*T allele was significantly associated with higher low-density lipoprotein cholesterol (LDL-C) and ApoB levels (P=0.007 and P=0.009 respectively). Haplotype analysis showed that the TC haplotype, having the minor rs4845625*T allele, was related simultaneously with increased levels of CRP, LDL-C and ApoB levels, thus could be considered as a risk factor. Our investigation detects for the first time an independent effect of rs4845625 on LDL-C and ApoB traits, explaining an important range of those traits variability (3.49 and 5.57% respectively). Our findings might be of high clinical significance in pharmacogenomics studies of tocilizumab for which IL-6R is target.

Familial liability to psychosis is a risk factor for multimorbidity in people with psychotic disorders and their unaffected siblings.

BACKGROUND: Multimorbidity may impose an overwhelming burden on patients with psychosis and is affected by gender and age. Our aim is to study the independent role of familial liability to psychosis as a risk factor for multimorbidity. METHODS: We performed the study within the framework of the Genetic Risk and Outcome of Psychosis (GROUP) project. Overall, we compared 1024 psychotic patients, 994 unaffected siblings and 566 controls on the prevalence of 125 lifetime diseases, and 19 self-reported somatic complaints. Multimorbidity was defined as the presence of two or more complaints/diseases in the same individual. Generalized linear mixed model (GLMM) were used to investigate the effects of gender, age (adolescent, young, older) and familial liability (patients, siblings, controls) and their interactions on multimorbidity. RESULTS: Familial liability had a significant effect on multimorbidity of either complaints or diseases. Patients had a higher prevalence of multimorbidity of complaints compared to siblings (OR 2.20, 95% CI 1.79-2.69, P<0.001) and to controls (3.05, 2.35-3.96, P<0.001). In physical health multimorbidity, patients (OR 1.36, 95% CI 1.05-1.75, P=0.018), but not siblings, had significantly higher prevalence than controls. Similar finding were observed for multimorbidity of lifetime diseases, including psychiatric diseases. Significant results were observed for complaints and disease multimorbidity across gender and age groups. CONCLUSION: Multimorbidity is a common burden, significantly more prevalent in patients and their unaffected siblings. Familial liability to psychosis showed an independent effect on multimorbidity; gender and age are also important factors determining multimorbidity.

Frequency Evaluation of T6235C (m1) and A4889G (m2) Polymorphisms of CYP1A1 Gene in a Healthy Population from the west of Mazandaran Province, Iran.

CYP1A1 is an important phase I xenobiotic metabolizing enzyme involved in the metabolism of numbers of toxins, endogenous hormones and drugs. Polymorphisms in this phase I gene can alter enzyme activity and induction, also are known to be associated with cancer susceptibility related to environmental toxins and hormone exposure. The present study was aimed to determine the frequencies of commonly known functional polymorphismsof CYP1A1 gene including CYP1A1 m1 (MspI), and CYP1A1 m2 (Ile-Val) in a healthy population from the west of Mazandaran province, Iran. A total of 200 unrelated healthy subjects from Mazandaran province, residing in Tonekabon city, coming for blood donating at Tonekabon Blood Transfusion Center were enrolled. Genomic DNA was extracted from peripheral blood lymphocytes of each subject. All subjects were genotyped for CYP1A1 m1 (T>C) and m2 (A>G) by polymerase chain reaction-restriction fragment length polymorphism method. The frequencies of the TT(wt/wt), TC(wt/mt) and CC(mt/mt) genotypes were as 65.5%, 32.0% and 2.5% respectively for m1 and frequencies of the AA(wt/wt), AG(wt/mt) and GG(mt/mt) genotypes were as 84.5%, 15% and 0.5% respectively for the m2. The frequencies of T and C alleles in the population were 81.5% and 18.5% respectively and the frequencies of A and G alleles were 92% and 8% respectively. Results of the present study might be important in understanding the distribution of CYP1A1 (m1) and CYP1A1 (m2) polymorphisms in Mazandaran province of Iran. Moreover, these results may determine the susceptibilities of individuals towards environmental procarcinogens that result in several cancers.

Cognitive subtypes in non-affected siblings of schizophrenia patients: characteristics and profile congruency with affected family members.

BACKGROUND: Although cognitive subtypes have been suggested in schizophrenia patients, similar analyses have not been carried out in their non-affected siblings. Subtype classification may provide more insight into genetically driven variation in cognitive function. We investigated cognitive subtypes in siblings. METHOD: Cluster analyses were performed in 654 non-affected siblings, on a cognitive battery that included tests of attention, intellectual function and episodic memory. Resulting subtypes in the siblings were analyzed for cognitive, demographic and clinical characteristics and compared with those of their probands. RESULTS: Three sibling subtypes of cognitive function were distinguished: 'normal', 'mixed' and 'impaired'. Normal profile siblings (n = 192) were unimpaired on cognitive tests, in contrast to their proband (n = 184). Mixed profile siblings (n = 228) and their probands (n = 222) had a more similar performance pattern. Impaired profile siblings had poorer functional outcomes (n = 234) and their profile was almost identical to that of their proband (n = 223). Probands with cognitively impaired siblings could be distinguished from other schizophrenia patients by their own cognitive performance. They also had poorer clinical characteristics, including achievement of symptomatic remission. CONCLUSIONS: Unaffected siblings of patients with schizophrenia are heterogeneous with respect to cognitive function. The poorer the cognitive profile of the sibling, the higher the level of correspondence with the proband. The sibling's cognitive subtype was predictive for disease course in the proband. Distinguishing cognitive subtypes of unaffected siblings may be of relevance for genetic studies.

Polymorphisms in the TLR6 gene associated with the inverse association between childhood acute lymphoblastic leukemia and atopic disease.

Little is known about the etiology of childhood acute lymphoblastic leukemia (ALL). The presence of atopic disease has been shown to protect against developing childhood ALL. The aim of this study was to examine whether single nucleotide polymorphisms (SNPs) in innate immunity genes previously associated with atopic disease, can elucidate the inverse association between childhood ALL and atopic disease. We studied 525 children, including 192 with childhood ALL, 149 with atopic disease and 184 healthy control subjects. We compared genotype distributions of 29 SNPs in genes of TLR2, TLR4, TLR6, TLR9, TLR10 and CD14 between the three groups and corrected for multiple testing. The genotype distributions of two SNPs in the TLR6 gene, rs5743798 and rs6531666, differed significantly between children with ALL, children with atopic disease and control subjects. Particularly in children with atopic eczema, risk alleles for atopic disease were observed more often than in control subjects, and less often in children with ALL than in control subjects. These findings support the immune surveillance hypothesis as an explanation for the protective association of atopic disease on childhood ALL. Further investigation is warranted to examine in more detail the role of innate immunity in the development of childhood ALL.

Association between age, IL-10, IFNγ, stimulated C-peptide and disease progression in children with newly diagnosed Type 1 diabetes.

AIMS: The relation of disease progression and age, serum interleukin 10 (IL-10) and interferon gamma (IFNγ) and their genetic correlates were studied in paediatric patients with newly diagnosed Type 1 diabetes. METHODS: Two hundred and twenty-seven patients from the Hvidoere Study Group were classified in four different progression groups as assessed by change in stimulated C-peptide from 1 to 6 months. CA repeat variants of the IL-10 and IFNγ gene were genotyped and serum levels of IL-10 and IFNγ were measured at 1, 6 and 12 months. RESULTS: IL-10 decreased (P < 0.001) by 7.7% (1 month), 10.4% (6 months) and 8.6% (12 months) per year increase in age of child, while a twofold higher C-peptide concentration at 1 month (p = 0.06), 6 months (P = 0.0003) and 12 months (P = 0.02) was associated with 9.7%, 18.6% and 9.7% lower IL-10 levels, independent of each other. IL-10 concentrations did not associate with the disease progression groups. By contrast, IFNγ concentrations differed between the four progression groups at 6 and 12 months (P = 0.02 and P = 0.01, respectively); patients with rapid progressing disease had the highest levels at both time points. Distribution of IL-10 and IFNγ genotypes was equal among patients from the progression groups. CONCLUSION: IL-10 serum levels associate inversely with age and C-peptide. As age and C-peptide also associate, a triangular association is proposed. Genetic influence on IL-10 production seems to be masked by distinct disease mechanisms. Increased serum IFNγ concentrations associate with rapid disease progression. Functional genetic variants do not associate with a single progression pattern group, implying that disease processes override genetically predisposed cytokine production.

Association of polymorphisms in the TLR4 gene with the risk of developing neutropenia in children with leukemia.

Infections are a major cause of morbidity and mortality in children with acute lymphoblastic leukemia (ALL). Susceptibility to infections increases as the neutrophil count decreases. Despite identical treatment patients vary considerably in the number of neutropenic episodes. Toll-like receptor 4 (TLR4) has been shown to have a role in inhibiting apoptosis of neutrophils. Therefore, we hypothesized that polymorphisms in the TLR4 gene may influence the number of chemotherapy-induced neutropenic episodes. Eight single-nucleotide polymorphisms (SNPs) of the TLR4 gene were determined in 194 children aged 0-17 years, who were diagnosed with ALL. We compared the genotype distributions of the SNPs with the frequency of neutropenic episodes during treatment with chemotherapeutic regimens. The number of neutropenic episodes varied from 0 to 17, with a median of four neutropenic episodes. Four SNPs in the TLR4 gene (rs10759931, rs11536889, rs1927911 and rs6478317) were associated with an increased risk of developing chemotherapy-induced neutropenia, each sustaining correction for multiple testing. Further studies are required to elucidate whether pediatric patients with ALL with the particular SNPs in the TLR4 gene also experience more infections and would benefit from prophylactic antibiotic treatment, by a reduction of morbidity and mortality due to infections.

Association of the CLCA1 p.S357N variant with meconium ileus in European patients with cystic fibrosis.

In Cftr-/- mice that mostly die because of intestinal obstruction, intestinal expression of Clca3 is decreased, whereas upregulation of Clca3 results in amelioration of intestinal disease. The aim of the study was to investigate whether the p.S357N variant in CLCA1, the human orthologue of Clca3, acts as a modifier gene in a cohort of 682 European patients with cystic fibrosis (CF)-99 patients with meconium ileus. The 357SS genotype was significantly overrepresented in both patients with meconium ileus and also with a severe CFTR genotype (P = 0.009) and in p.F508del homozygotes (P = 0.002). This suggests that CLCA1 has similar important functions in CF-related intestinal obstruction in humans as in Cftr-/- mice.

Association of ATG16L1 and IRGM genes polymorphisms with inflammatory bowel disease: a meta-analysis approach.

The aim of this study was to determine the role of the ATG16L1 (rs2241880) and IRGM (rs13361189 and rs4958847) genes polymorphism in Crohn's disease (CD) and ulcerative colitis (UC). Our study included 557 CD and 425 UC patients and 672 ethnically matched Spanish controls and a meta-analysis with the data published to date. The polymorphisms were genotyped using predesigned TaqMan single nucleotide polymorphism genotyping assays. There was a statistically significant difference in the distribution of the ATG16L1 rs2241880 G allele between CD patients and controls in the Spanish population: P=6.5 x 10(-9), odds ratio (OR)=1.62. Although no differences were observed between UC patients and controls in the Spanish cohort, a meta-analysis demonstrated that the ATG16L1 G allele increase significantly risk for UC (P=0.0003, pooled OR=1.08). In addition, our meta-analysis data showed that IRGM rs13361189 and rs4958847 polymorphisms were associated with CD (rs13361189 C allele P=1.07 x 10(-19), pooled OR=1.34; rs4958847 A allele P=2.78 x 10(-17), pooled OR=1.31) and UC (rs13361189 P=0.0069, pooled OR=1.16; rs4958847 P=0.014, pooled OR=1.13). In conclusion, our results confirm the ATG16L1 rs2241880 and IRGM rs13361189 and rs4958847 polymorphisms as important markers for CD susceptibility and indicate that these variants are also associated with UC.

Does the genetic and familial background of males undertaking ICSI affect the outcome?

PURPOSE: To investigate whether the success rate of ICSI is (1) related to the etiology of infertility or (2) adversely affected by a family history of potential genetic disorders. METHODS: All men with an ICSI indication in our hospital between 1994 and 2005 were included in our cohort study. Data on the ICSI process, etiology of infertility, and family history were collected. ICSI success rates of infertility subgroups and a subgroup with a positive family history were compared to a group with unknown etiology and a negative family history. RESULTS: There was no significant difference in clinical pregnancy or delivery rates between the subgroups. Couples achieving a pregnancy underwent significantly more ICSI cycles compared to couples not achieving a pregnancy. CONCLUSION: Our results suggest that the success rate of ICSI treatment is not related to the cause of infertility or a family history positive for potential genetic disorders.

HFE variants, APOE and Alzheimer's disease: findings from the population-based Rotterdam study.

Iron is a reactive oxygen species and has been implicated in the pathogenesis of Alzheimer's disease (AD). In a population-based cohort study, including 268 incident AD patients and 2079 control individuals, we investigated the influence of the HFE C282Y and H63D variants and the apolipoprotein E4 (APOE epsilon 4) allele on the incidence, and age at onset of AD. There was no significant difference in the frequency of HFE variants in AD patients compared to controls. There was no significant effect modification by the APOE epsilon 4 allele. The mean age at onset was earlier in H63D homozygotes compared to non-carriers of this variant, in men (76.9+/-3.2 compared to 82.2+/-1.7) and women (82.1+/-3.9 compared to 84.5+/-1.7). In addition, in APOE epsilon 4 carriers, the mean age at onset of AD was earlier in men homozygous for the H63D variant (73.2+/-2.1 versus 78.7+/-1.6, p=0.05). Our results suggest that HFE variants are not strong determinants of AD in the general population but may modify the age of onset.

Study of the association between the CAPSL-IL7R locus and type 1 diabetes.

AIMS/HYPOTHESIS: In the past few years, several genes outside the MHC region have been described as new susceptibility genetic factors to type 1 diabetes. An association between CAPSL-rs1445898 and type 1 diabetes was reported in a large white population and corroborated in a genome-wide analysis, which also found an association with IL7R, which is located adjacent to CAPSL. The aim of this study was to replicate the aforementioned associations in independent cohorts. METHODS: We analysed two CAPSL (rs1010601 and rs1445898) and three IL7R (rs6897932, rs987106 and rs3194051) polymorphisms. All these single nucleotide polymorphisms (SNPs) were genotyped using TaqMan minor groove binder chemistry in 301 unrelated Spanish type 1 diabetes patients and 646 healthy controls. Additionally, the associated CAPSL SNP rs1445898 was genotyped in a Dutch cohort consisting of 429 type 1 diabetes patients and 720 healthy controls. RESULTS: The homozygous mutant genotype of the CAPSL SNP rs1445898 showed a trend towards a protective effect in the overall Spanish cohort (OR [95% CI] 0.70 [0.44-1.09]; p = 0.09) and in the Dutch cohort (OR [95% CI] 0.74 [0.51-1.05]; p = 0.09). Pooling of both cohorts was performed, yielding a statistically significant difference (Mantel-Haenszel OR 0.71; p = 0.005). This protective effect was significantly different in early-onset vs late-onset Spanish patients (OR [95% CI] 0.26 [0.10-0.65]; p = 0.001). Similarly, in the early-onset subgroup, the homozygous mutant genotype of the IL7R SNP rs6897932 showed a similar protective effect (OR [95% CI] 0.18 [0.02-0.94]; p = 0.02). CONCLUSIONS/INTERPRETATION: In summary, we describe an independent replication of the association between the CAPSL-IL7R locus and type 1 diabetes, especially for early-onset type 1 diabetes patients.

Relation of circulating concentrations of chemokine receptor CCR5 ligands to C-peptide, proinsulin and HbA1c and disease progression in type 1 diabetes.

Th1 related chemokines CCL3 and CCL5 and Th2 related CCL4 as ligands of the receptor CCR5 contribute to disease development in animal models of type 1 diabetes. In humans, no data are available addressing the role of these chemokines regarding disease progression and remission. We investigated longitudinally circulating concentrations of CCR5 ligands of 256 newly diagnosed patients with type 1 diabetes. CCR5 ligands were differentially associated with beta-cell function and clinical remission. CCL5 was decreased in remitters and positively associated with HbA1c suggestive of a Th1 associated progression of the disease. Likewise, CCL3 was negatively related to C-peptide and positively associated with the beta-cell stress marker proinsulin but increased in remitters. CCL4 associated with decreased beta-cell stress shown by negative association with proinsulin. Blockage of chemokines or antagonism of CCR5 by therapeutic agents such as maraviroc may provide a new therapeutic target to ameliorate disease progression in type 1 diabetes.

Modelling KIR-HLA genotype disparities in type 1 diabetes.

We previously reported that a disparate distribution between killer cell immunoglobulin-like receptor (KIR) and human leukocyte antigen (HLA) class 1 genes is associated with susceptibility to develop type 1 diabetes. Here we compare multiple models which reflect the combined genotype effects of combinations of functional inhibitory and activating KIRs in relation to HLA in an extended cohort of patients with juvenile-onset type 1 diabetes and non-diabetic control subjects. Our results suggest that autoimmunity in type 1 diabetes is mainly associated with a decrease in inhibitory KIR-HLA genotype combinations, while the influence of activating KIR genotypes seems redundant. However, logistic regression showed that activating KIR genotypes do influence the overall hierarchy of protection/susceptibility as reflected by composite inhibitory and activating KIR-HLA genotype models.

Association of immune mediators at diagnosis of Type 1 diabetes with later clinical remission.

AIMS: We tested the hypothesis that systemic concentrations of cytokines, chemokines or soluble cytokine receptors predict or accompany clinical remission in Type 1 diabetes (T1D). METHODS: In a prospective, multicentre study, 48 patients with newly diagnosed T1D and 55 age-matched healthy control subjects were investigated. Blood was drawn 3-7 days after the diagnosis and then 3-4 months later. Patients were grouped into partial remitters or non-remitters by the degree of clinical improvement defined by HbA(1c) (threshold 7.5%) and daily insulin dose (threshold 0.38 IU/kg/day). Systemic concentrations of 17 immune mediators were analysed in serum or plasma. In addition, autoantibodies against insulin (IAA), IA-2 (IA-2A) and GAD65 (GADA) were quantified. RESULTS: All 17 immune mediators showed remarkable intra-individual stability in their systemic concentrations over time. As a consequence, partial remission was not accompanied by changes in mediator levels except for a moderate decrease of interleukin (IL)-1ra concentrations (P = 0.02) and IL-10 concentrations (P = 0.01) in non-remitters. Baseline levels were associated with the later clinical course in that low levels of interferon gamma (P = 0.01), IL-10 (P = 0.03) and IL-1R1 (P = 0.009) concentrations were observed in partial remitters. CONCLUSIONS: We conclude that the systemic immunoregulatory state at diagnosis of T1D is predictive of clinical improvement during the remission phase. There was no general change in systemic immune reactivity in the months after diagnosis and initiation of insulin therapy.

The H63D variant in the HFE gene predisposes to arthralgia, chondrocalcinosis and osteoarthritis.

OBJECTIVES: To investigate the relation between the HFE C282Y and H63D variants with arthralgia and joint pathology in the population-based Rotterdam Study. METHODS: From a cohort of 7983 people aged 55 years and over, 2095 randomly drawn subjects were genotyped for C282Y and H63D variants. We compared the frequency of arthralgia, and the presence of chondrocalcinosis, osteophytes, joint space narrowing and radiographic osteoarthritis in hand, hip and knee joints, and Heberden's nodes in carriers of HFE variants with that in non-carriers. RESULTS: Overall, there was a significantly higher frequency of arthralgia (odds ratio 1.6; 95% CI 1.0 to 2.6), oligoarthralgia (2.3; 1.2 to 4.4) and Heberden's nodes (2.0; 1.1 to 3.8) in H63D homozygotes compared with non-carriers. In subjects aged 65 years or younger, H63D homozygotes had significantly more often polyarthralgia (3.1; 1.3 to 7.4), chondrocalcinosis in hip or knee joints (4.7; 1.2 to 18.5), and more hand joints with osteophytes (6.1+/-1.0 vs 4.4+/-0.3), space narrowing (2.8+/-0.5 vs 1.0+/-0.1), radiographic osteoarthritis (4.4+/-0.7 vs 2.0+/-0.2) and Heberden's nodes (3.1; 1.3 to 12.8) than non-carriers. We found no relation of arthralgia or joint pathology to C282Y, but compound heterozygotes had a significantly higher frequency of arthralgia (2.9; 1.0 to 9.3), chondrocalcinosis in hip joints (6.5; 1.8 to 22.3), and an increased number of osteophytes in knee (6.9+/-1.2, n = 5 vs 2.4+/-0.1) joints at a later age (>65 years). CONCLUSIONS: The HFE H63D variant may explain, at least in part, the prevalence of arthralgia in multiple joints sites, chondrocalcinosis, and hand osteoarthritis in the general population.

Association of interferon-gamma and interleukin 10 genotypes and serum levels with partial clinical remission in type 1 diabetes.

We studied whether serum interferon (IFN)-gamma or interleukin (IL)-10 levels and their corresponding functional polymorphic genotypes are associated with partial remission of type 1 diabetes (T1D). A multi-centre study was undertaken in patients with newly diagnosed T1D and matched controls. T1D patients were followed for 3 months and characterized for remission status. Partial clinical remission was defined as a daily insulin dose

Heritability of serum iron, ferritin and transferrin saturation in a genetically isolated population, the Erasmus Rucphen Family (ERF) Study.

BACKGROUND: Iron has been implicated in the pathogenesis of various disorders. Mutations in the HFE gene are associated with an increase in serum iron parameters. The aim of this study was to estimate the heritability in serum iron parameters explained by HFE. METHODS: Ninety families (980 subjects) were included in the present analysis. Heritability estimation was conducted using the variance component method. The likelihood ratio test was used to compare models. Phenotypic and genetic correlations between serum iron parameters were calculated. RESULTS: The heritability (h(2) +/- SE) estimates were 0.23 +/- 0.07 (p < 0.0001) for iron, 0.29 +/- 0.09 (p < 0.0001) for ferritin and 0.28 +/- 0.07 (p < 0.0001) for transferrin saturation while adjusting for age, age(2) and sex. The HFE genotypes explained between 2 to 6% of the sex and age-adjusted variance in serum iron, ferritin and transferrin saturation. There was a high genetic correlation between serum iron parameters, suggesting pleiotropy between these traits. CONCLUSION: A substantial proportion of the variance of iron, ferritin and transferrin saturation can be explained by additive genetic effects, independent of sex and age. The HFE genotypes explained a considerable proportion of serum iron parameters and may be an important factor in the complex iron network.