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Autoimmune muscle diseases (myositis) comprise a group of complex phenotypes influenced by genetic and environmental factors. To identify genetic risk factors in patients of European ancestry, we conducted a genome-wide association study (GWAS) of the major myositis phenotypes in a total of 1710 cases, which included 705 adult dermatomyositis; 473 juvenile dermatomyositis; 532 polymyositis; and 202 adult dermatomyositis, juvenile dermatomyositis or polymyositis patients with anti-histidyl tRNA synthetase (anti-Jo-1) autoantibodies, and compared them with 4724 controls. Single-nucleotide polymorphisms showing strong associations (P < 5 × 10−8) in GWAS were identified in the major histocompatibility complex (MHC) region for all myositis phenotypes together, as well as for the four clinical and autoantibody phenotypes studied separately. Imputation and regression analyses found that alleles comprising the human leukocyte antigen (HLA) 8.1 ancestral haplotype (AH8.1) defined essentially all the genetic risk in the phenotypes studied. Although the HLA DRB1*03:01 allele showed slightly stronger associations with adult and juvenile dermatomyositis, and HLA B*08:01 with polymyositis and anti-Jo-1 autoantibody-positive myositis, multiple alleles of AH8.1 were required for the full risk effects. Our findings establish that alleles of the AH8.1haplotype comprise the primary genetic risk factors associated with the major myositis phenotypes in geographically diverse Caucasian populations.

Correction to: Molecular Psychiatry (2017) 22, 336–345; doi:10.1038/mp.2016.244;published online 17 January 2017 Data access for several cohorts used in this study was provided by the National Center for Biotechnology Information (NCBI) database of Genotypes and Phenotypes (dbGaP). dbGaP accession numbers for these cohorts were as follows

Dysfunction of the serotonergic pathway disrupts normal cognitive functioning and is believed to be the underlying basis for a variety of psychiatric disorders. Two functional polymorphisms within the serotonin transporter (SLC6A4) gene (promoter 44 bp insertion/deletion (HTTLPR) and an intron two 16 or 17 bp variable number tandem repeat (VNTR2)) have been extensively studied in psychiatric conditions but not in the cognitive functioning of normal individuals. We have investigated these two polymorphisms for association with both the level of cognitive abilities and their decline with age using a cohort consisting of over 750 elderly nondemented individuals with a follow-up of up to 15 years. We found that volunteers homozygous for the VNTR2 12 allele had a faster rate of decline for all cognitive tests. This reached significance for both tests of fluid intelligence (novel problem solving) (AH1 P=0.002, AH2 P=0.014), the test of semantic memory (P=0.010) and general cognitive ability (P=0.006). No association was observed between the HTTLPR polymorphism and the rate of cognitive decline when analysed either independently or in combination with the VNTR2 polymorphism based on their influence on expression in vitro. No associations were observed between the two polymorphisms and the baseline level of cognitive abilities. This is only the second gene that has been reported to regulate the rate of cognitive decline in nondemented individuals and may be a target for the treatment of cognitive impairment in the elderly.

General intelligence is a heritable trait that is a risk factor for both the onset of dementia and the rate of cognitive decline in community-dwelling older persons. Previous studies screening for quantitative trait loci (QTLs) that influence general intelligence in healthy individuals have identified four loci, two of which are located within the genes insulin-like growth factor 2 receptor (IGF2R) and the Msx1 homeobox. Here, we report the finding of another QTL associated with general intelligence that is located within exon 2 of the cathepsin D (CTSD) gene. A group of 767 healthy adults with a follow-up period of over 15 years have been analyzed for cross-sectional and longitudinal trends in cognitive change using the Heim intelligence test score (AH4-1). We observed a significant association (P=0.01) between a functional C>T (Ala>Val) transition within exon 2 of the CTSD gene that increases the secretion of pro-CTSD from the cell, and the AH4-1 score at initial testing on entry to the longitudinal study. Interestingly, CTSD is transported by IGF2R from the trans Golgi network to the lysosome.

Nut allergy is an important and potentially life threatening food allergy with a prevalence of one in 150 children in the UK population. STAT6 (signal transducer and activator of transcription) is an important molecule in the induction and regulation of an allergic response, which maps to chromosome 12q in a region previously linked with total serum IgE concentration and atopy in different populations. We have examined the frequency of a single nucleotide polymorphism (SNP) in the 3'UTR region of STAT6 gene in 71 UK Caucasoid patients diagnosed with nut allergy and 45 atopic patients without nut allergy using PCR-RFLP and compared these with 184 UK healthy controls. The STAT6 G allele frequency was significantly increased in nut allergy patients compared with blood donor controls (P < 0.0001, OR = 2.9, 95% CI: 1.7-4.9), which was under a recessive model (GG vs GA+AA, P = 0.0001, OR = 3.2, 95% CI: 1.7-5.8) but not in atopic patients without nut allergy. The G allele was most frequent in the severe cases and GG homozygosity was associated with the increased risk of severe reaction (OR = 3.9, 95% CI: 1.9-8.3). We conclude that STAT6 3'UTR polymorphism is associated with susceptibility and severity in nut allergic patients in our population.

The association between susceptibility to multiple sclerosis (MS) and the class II MHC allele HLA-DRB1*15 is well established although a possible relationship between this allele and outcome in MS is less clear. HLA-DRB1 typing was performed on 375 unrelated white patients with clinically definite MS and on 367 healthy controls. Putative associations of the gene with outcome were examined by dividing patients into two groups: those with an EDSS of 0–5.5 (mild/moderate disease) and those with an EDSS of 6–10 (severe disease). In order to minimise the effects of disease variability patients with a disease duration of at least 10 years or 15 years were examined. As subsidiary HLA-DRB1*03 and HLA-DRB1*04 associations have been previously reported, the effect of these alleles was also examined. As expected, HLA-DRB1*15 was found more frequently in patients than in controls (P < 0.000001). HLA-DRB1*15 positive patients had a significantly earlier age at onset than HLA-DRB1*15 negative patients. No significant associations were noted between HLA-DRB1*15 and outcome in the total patient group or in patients with a disease duration of 10 years or longer. In patients with a disease duration of at least 15 years HLA-DRB1*15 negative status was associated with a worse prognosis, although this did not remain significant after correction for multiple testing. It is thus likely that the contribution of HLA in MS is primarily towards onset and initial triggering mechanisms rather than influencing disease progression, chronicity and severity

Matrix metalloproteinases (MMPs) are implicated in joint destruction in rheumatoid arthritis (RA). We investigated whether the 5A/6A polymorphism within the MMP-3 (stromelysin-1) gene promoter region is associated with disease outcome in 254 patients with established RA. Patients homozygous for the MMP-3 6A allele had more radiographic damage (measured by Larsen score) than those with other genotypes (109.8 vs 91.1, P=0.04). Patients with the 6A/6A genotype also had more functional impairment and higher serum proMMP-3 levels, although only the latter was significant (P=0.002). A possible association was found between homozygosity for the 6A allele and carriage of the RA-associated HLA-DRB1 shared epitope (SE). Combination of these factors was associated with more severe disease than the SE alone. The data suggest that the MMP-3 6A/6A genotype is associated with worse RA outcome, and that this genotype may have an additive effect with the SE on disease severity.

We have identified two novel polymorphisms in the transforming growth factor beta 2 (TGFbeta2) gene; an insertion in the 5'-untranslated region (5'UTR) and a single nucleotide polymorphism (SNP) in exon 1. A 895-bp fragment was analysed covering part of the 5'UTR and exon 1. Single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR) products was performed to detect sequence variations. This was followed by the sequencing of samples demonstrating distinct banding patterns. A 4-bp insertion (ACAA) in the 5'UTR and a SNP (G > A) within exon 1 was identified. The 5'UTR polymorphism was found to be common in three Caucasian populations from Spain, Turkey and the UK. Exon 1 polymorphism is rare and results in an R to H amino acid substitution in codon 91. Both polymorphisms may prove useful for investigating possible associations of TGFbeta2 with disease.