Intragenic SNP haplotypes associated with 84dup18 mutation in TNFRSF11A in four FEO pedigrees suggest three independent origins for this mutation.

Familial expansile osteolysis (FEO) is a rare disorder causing bone dysplasia. The clinical features of FEO include early-onset hearing loss, tooth destruction, and progressive lytic expansion within limb bones causing pain, fracture, and deformity. An 18-bp duplication in the first exon of the TNFRSF11A gene encoding RANK has been previously identified in four FEO pedigrees. Despite having the identical mutation, phenotypic variations among affected individuals of the same and different pedigrees were noted. Another 18-bp duplication, one base proximal to the duplication previously reported, was subsequently found in two unrelated FEO patients. Finally, mutations overlapping with the mutations found in the FEO pedigrees have been found in ESH and early-onset PDB pedigrees. An Iranian FEO pedigree that contains six affected individuals dispersed in three generations has previously been introduced; here, the clinical features of the proband are reported in greater detail, and the genetic defect of the pedigree is presented. Direct sequencing of the entire coding region and upstream and downstream noncoding regions of TNFRSF11A in her DNA revealed the same 18-bp duplication mutation as previously found in the four FEO pedigrees. Additionally, eight sequence variations as compared to the TNFRSF11A reference sequence were identified, and a haplotype linked to the mutation based on these variations was defined. Although the mutation in the Iranian and four of the previously described FEO pedigrees was the same, haplotypes based on the intragenic SNPs suggest that the mutations do not share a common descent.

Genetic variants of complement factor H gene are not associated with premature coronary heart disease:A family-based study in the Irish population

Background: The complement factor H (CFH) gene has been recently confirmed to play an essential role in the development of age-related macular degeneration (AMD). There are conflicting reports of its role in coronary heart disease. This study was designed to investigate if, using a family-based approach, there was an association between genetic variants of the CFH gene and risk of early-onset coronary heart disease. Methods: We evaluated 6 SNPs and 5 common haplotypes in the CFH gene amongst 1494 individuals in 580 Irish families with at least one member prematurely affected with coronary heart disease. Genotypes were determined by multiplex SNaPshot technology. Results: Using the TDT/S-TDT test, we did not find an association between any of the individual SNPs or any of the 5 haplotypes and early-onset coronary heart disease. Conclusion: In this family-based study, we found no association between the CFH gene and early-onset coronary heart disease. © 2007 Meng et al; licensee BioMed Central Ltd.

BRCA1: mechanisms of inactivation and implications for management of patients.

The BRCA1 gene was cloned in 1994 as one of the genes that conferred genetic predisposition to early-onset breast and ovarian cancer. Since then, a genetic test for identification of high-risk individuals has been developed. Despite being implicated in many important cellular pathways, including DNA repair and regulation of transcription, the exact mechanism by which inactivation of BRCA1 might lead to malignant transformation of cells remains unknown. We examine the mechanisms that underlie inactivation of BRCA1 and assess how they affect management of patients, in terms of both primary and secondary cancer prevention strategies. Furthermore, we look at the potential usefulness of BRCA1 as a prognostic tool and as a predictive marker of response to different classes of drugs. Finally, throughout this review, we draw links between the functional consequences of BRCA1 inactivation, in terms of key cellular signalling pathways, and how they might explain specific clinical observations in individuals who carry mutations in the gene.

Proteomic analysis of circulating immune complexes in juvenile idiopathic arthritis reveals disease-associated proteins

Juvenile idiopathic arthritis reflects a group of clinically heterogeneous arthritides hallmarked by elevated concentrations of circulating immune complexes. In this study, the circulating immune complex proteome was examined to elucidate disease-associated proteins that are overexpressed in patients with an aggressive, and at times destructive, disease phenotype. To solve this proteome, circulating immune complexes were isolated from the sera of patients with chronic, erosive or early-onset, aggressive disease and from patients in medical remission or healthy controls subsequent to protein separation by 2-DE. Thirty-seven protein spots were overexpressed in the circulating immune complexes of the aggressive disease groups as compared to controls, 28 of which have been confidently identified to date. Proteolytic fragments of glyceraldehyde-3-phosphate dehydrogenase, serotransferrin, and a-1-antitrypsin have been identified among others. In total, these 28 putative disease-associated proteins most definitely contribute to immune complex formation and likely have a significant role in disease etiology and pathogenesis. Moreover, these proteins represent markers of aggressive disease, which could aid in diagnosis and management strategies, and potential therapeutic targets to prevent or control disease outcome. This is the first in-depth analysis of the circulating immune complex proteome in juvenile idiopathic arthritis.

Anti-apoptotic effects of Z alpha-1 antitrypsin in human bronchial epithelial cells.

α1-antitrypsin (α1-AT) deficiency is a genetic disease which manifests as early-onset emphysema or liver disease. Although the majority of α1-AT is produced by the liver, it is also produced by bronchial epithelial cells, amongst others, in the lung. Herein, we investigate the effects of mutant Z α1-AT (ZAAT) expression on apoptosis in a human bronchial epithelial cell line (16HBE14o-) and delineate the mechanisms involved.

Control, M variant α1-AT (MAAT)- or ZAAT-expressing cells were assessed for apoptosis, caspase-3 activity, cell viability, phosphorylation of Bad, nuclear factor (NF)-κB activation and induced expression of a selection of pro- and anti-apoptotic genes.

Expression of ZAAT in 16HBE14o- cells, like MAAT, inhibited basal and agonist-induced apoptosis. ZAAT expression also inhibited caspase-3 activity by 57% compared with control cells (p = 0.05) and was a more potent inhibitor than MAAT. Whilst ZAAT had no effect on the activity of Bad, its expression activated NF-κB-dependent gene expression above control or MAAT-expressing cells. In 16HBE14o- cells but not HEK293 cells, ZAAT upregulated expression of cIAP-1, an upstream regulator of NF-κB. cIAP1 expression was increased in ZAAT versus MAAT bronchial biopsies.

The data suggest a novel mechanism by which ZAAT may promote human bronchial epithelial cell survival.

Lack of Association Between the Trp719Arg Polymorphism in Kinesin-Like Protein-6 and Coronary Artery Disease in 19 Case-Control Studies

Objectives: We sought to replicate the association between the kinesin-like protein 6 (KIF6) Trp719Arg polymorphism (rs20455), and clinical coronary artery disease (CAD).
Background: Recent prospective studies suggest that carriers of the 719Arg allele in KIF6 are at increased risk of clinical CAD compared with noncarriers.
Methods: The KIF6 Trp719Arg polymorphism (rs20455) was genotyped in 19 case-control studies of nonfatal CAD either as part of a genome-wide association study or in a formal attempt to replicate the initial positive reports.
Results: A total of 17,000 cases and 39,369 controls of European descent as well as a modest number of South Asians, African Americans, Hispanics, East Asians, and admixed cases and controls were successfully genotyped. None of the 19 studies demonstrated an increased risk of CAD in carriers of the 719Arg allele compared with noncarriers. Regression analyses and fixed-effects meta-analyses ruled out with high degree of confidence an increase of <2% in the risk of CAD among European 719Arg carriers. We also observed no increase in the risk of CAD among 719Arg carriers in the subset of Europeans with early-onset disease (younger than 50 years of age for men and younger than 60 years of age for women) compared with similarly aged controls as well as all non-European subgroups.
Conclusions: The KIF6 Trp719Arg polymorphism was not associated with the risk of clinical CAD in this large replication study.

Oromotor dysfunction and communication impairments in children with cerebral palsy: a Register study

Aim  To report the prevalence, clinical associations, and trends over time of oromotor dysfunction and communication impairments in children with cerebral palsy (CP).

Method  Multiple sources of ascertainment were used and children followed up with a standardized assessment including motor speech problems, swallowing/chewing difficulties, excessive drooling, and communication impairments at age 5 years.

Results  A total of 1357 children born between 1980 and 2001 were studied (781 males, 576 females; median age 5y 11mo, interquartile range 3–9y; unilateral spastic CP, n=447; bilateral spastic CP, n=496; other, n=112; Gross Motor Function Classification System [GMFCS] level: I, 181; II, 563; III, 123; IV, 82; IV, 276). Of those with ‘early-onset’ CP (n=1268), 36% had motor speech problems, 21% had swallowing/chewing difficulties, 22% had excessive drooling, and 42% had communication impairments (excluding articulation defects). All impairments were significantly related to poorer gross motor function and intellectual impairment. In addition, motor speech problems were related to clinical subtype; swallowing/chewing problems and communication impairments to early mortality; and communication impairments to the presence of seizures. Of those with CP in GMFCS levels IV to V, a significant proportion showed a decline in the rate of motor speech impairment (p=0.008) and excessive drooling (p=0.009) over time.

Interpretation  These impairments are common in children with CP and are associated with poorer gross motor function and intellectual impairment.

The prevalence of alpha-1 antitrypsin deficiency in Ireland

Background: Alpha-1 antitrypsin deficiency (AATD) results from mutations in the SERPINA1 gene and classically presents with early-onset emphysema and liver disease. The most common mutation presenting with clinical evidence is the Z mutation, while the S mutation is associated with a milder plasma deficiency. AATD is an under-diagnosed condition and the World Health Organisation recommends targeted detection programmes for AATD in patients with chronic obstructive pulmonary disease (COPD), non-responsive asthma, cryptogenic liver disease and first degree relatives of known AATD patients.

Mutation altering the miR-184 seed region causes keratoconus with cataract

MicroRNAs (miRNAs) bind to complementary sequences within the 3? untranslated region (UTR) of mRNAs from hundreds of target genes, leading either to mRNA degradation or suppression of translation. We found that a mutation in the seed region of miR-184 (MIR184) is responsible for familial severe keratoconus combined with early-onset anterior polar cataract, by deep sequencing of a linkage region known to contain the mutation. The mutant form fails to compete with miR-205 (MIR205) for overlapping target sites on the 3? UTRs of INPPL1 and ITGB4. Although these target genes and miR-205 are expressed widely, the phenotype is restricted to the cornea and lens because of the very high expression of miR-184 in these tissues. Our finding highlights the tissue-specificity of a gene network regulated by a miRNA. Awareness of the important function of miRNAs may aid identification of susceptibility genes and new therapeutic targets for treatment of both rare and common diseases.

Analysis of alteration of p75NTR processing and signalling by PS2 mutation and gamma-secretase inhibition

The presenilins (PSs) were identified as causative genes in cases of early-onset familial Alzheimer's disease (AD) and current evidence indicates that PSs are part of the gamma-secretase complex responsible for proteolytic processing of type I membrane proteins. p75NTR, a common neurotrophin receptor, was shown to be subject to gamma-secretase processing. However, it is not clear if the p75NTR downstream signal is altered in response to gamma-secretase cleavage, and further there is a possibility that AD-related PS mutations may affect this cleavage, resulting in pathogenic alterations in signal transduction. In this study, we confirmed that p75NTR downstream signalling is altered by PS2 mutation or gamma-secretase inhibition in SHSY-5Y cells. The activity of the small GTPase RhoA is strongly affected by these treatments. This study demonstrates that gamma-secretase and PS2 play an important role in regulating neurotrophin signal transduction and either mutation of PS2 or inhibition of gamma-secretase disturbs this function.

A whole-genome massively parallel sequencing analysis of BRCA1 mutant oestrogen receptor-negative and -positive breast cancers

BRCA1 encodes a tumour suppressor protein that plays pivotal roles in homologous recombination (HR) DNA repair, cell-cycle checkpoints, and transcriptional regulation. BRCA1 germline mutations confer a high risk of early-onset breast and ovarian cancer. In more than 80% of cases, tumours arising in BRCA1 germline mutation carriers are oestrogen receptor (ER)-negative; however, up to 15% are ER-positive. It has been suggested that BRCA1 ER-positive breast cancers constitute sporadic cancers arising in the context of a BRCA1 germline mutation rather than being causally related to BRCA1 loss-of-function. Whole-genome massively parallel sequencing of ER-positive and ER-negative BRCA1 breast cancers, and their respective germline DNAs, was used to characterize the genetic landscape of BRCA1 cancers at base-pair resolution. Only BRCA1 germline mutations, somatic loss of the wild-type allele, and TP53 somatic mutations were recurrently found in the index cases. BRCA1 breast cancers displayed a mutational signature consistent with that caused by lack of HR DNA repair in both ER-positive and ER-negative cases. Sequencing analysis of independent cohorts of hereditary BRCA1 and sporadic non-BRCA1 breast cancers for the presence of recurrent pathogenic mutations and/or homozygous deletions found in the index cases revealed that DAPK3, TMEM135, KIAA1797, PDE4D, and GATA4 are potential additional drivers of breast cancers. This study demonstrates that BRCA1 pathogenic germline mutations coupled with somatic loss of the wild-type allele are not sufficient for hereditary breast cancers to display an ER-negative phenotype, and has led to the identification of three potential novel breast cancer genes (ie DAPK3, TMEM135, and GATA4).

Present orientation, future orientation and alcohol use in Northern Irish adolescents

Earlier initiation into more problematic drinking behaviour has been found to be associated with more problematic drinking later in life. Research has suggested that a lower future time perspective (and higher present time perspective) is associated with health-compromising behaviours such as problematic alcohol use in college student, University undergraduate and general population samples. This study used a cross-sectional design to examine whether consideration of future consequences (CFC), assessed by the Consideration of Future Consequences Scale, was significantly related to drinking behaviour in a large sample (n=707) of Northern Irish adolescents. Alcohol use was self-reported by means of a composite measure of drinking behaviour. Demographic data were also gathered. After controlling for year in school (proxy for age), sex and for clustering at school level, lower future orientation and higher present orientation were found to be significantly associated with more problematic self-reported drinking behaviour. These results extend recent findings of a significant relationship between a foreshortened future time perspective and more problematic self-reported drinking behaviour in a UK sample of University undergraduates, to a large UK sample of adolescents. Given the relationship between early-onset drinking and more problematic use in later life, health promotion interventions might explore using the CFC construct in targeting adolescent drinkers.

Age- and Light-Dependent Development of Localised Retinal Atrophy in CCL2(-/-)CX3CR1(GFP/GFP) Mice

Previous studies have shown that CCL2/CX3CR1 deficient mice on C57BL/6N background (with rd8 mutation) have an early onset (6 weeks) of spontaneous retinal degeneration. In this study, we generated CCL2(-/-)CX3CR1(GFP/GFP) mice on the C57BL/6J background. Retinal degeneration was not detected in CCL2(-/-)CX3CR1(GFP/GFP) mice younger than 6 months. Patches of whitish/yellowish fundus lesions were observed in 17~60% of 12-month, and 30~100% of 18-month CCL2(-/-)CX3CR1(GFP/GFP) mice. Fluorescein angiography revealed no choroidal neovascularisation in these mice. Patches of retinal pigment epithelium (RPE) and photoreceptor damage were detected in 30% and 50% of 12- and 18-month CCL2(-/-)CX3CR1(GFP/GFP) mice respectively, but not in wild-type mice. All CCL2(-/-)CX3CR1(GFP/GFP) mice exposed to extra-light (~800lux, 6 h/day, 6 months) developed patches of retinal atrophy, and only 20-25% of WT mice which underwent the same light treatment developed atrophic lesions. In addition, synaptophysin expression was detected in the outer nucler layer (ONL) of area related to photoreceptor loss in CCL2(-/-)CX3CR1(GFP/GFP) mice. Markedly increased rhodopsin but reduced cone arrestin expression was observed in retinal outer layers in aged CCL2(-/-)CX3CR1(GFP/GFP) mice. GABA expression was reduced in the inner retina of aged CCL2(-/-)CX3CR1(GFP/GFP) mice. Significantly increased Müller glial and microglial activation was observed in CCL2(-/-)CX3CR1(GFP/GFP) mice compared to age-matched WT mice. Macrophages from CCL2(-/-)CX3CR1(GFP/GFP) mice were less phagocytic, but expressed higher levels of iNOS, IL-1ß, IL-12 and TNF-a under hypoxia conditions. Our results suggest that the deletions of CCL2 and CX3CR1 predispose mice to age- and light-mediated retinal damage. The CCL2/CX3CR1 deficient mouse may thus serve as a model for age-related atrophic degeneration of the RPE, including the dry type of macular degeneration, geographic atrophy.

Genetic Markers Enhance Coronary Risk Prediction in Men: The MORGAM Prospective Cohorts

Background: More accurate coronary heart disease (CHD) prediction, specifically in middle-aged men, is needed to reduce the burden of disease more effectively. We hypothesised that a multilocus genetic risk score could refine CHD prediction beyond classic risk scores and obtain more precise risk estimates using a prospective cohort design.

Methods: Using data from nine prospective European cohorts, including 26,221 men, we selected in a case-cohort setting 4,818 healthy men at baseline, and used Cox proportional hazards models to examine associations between CHD and risk scores based on genetic variants representing 13 genomic regions. Over follow-up (range: 5-18 years), 1,736 incident CHD events occurred. Genetic risk scores were validated in men with at least 10 years of follow-up (632 cases, 1361 non-cases). Genetic risk score 1 (GRS1) combined 11 SNPs and two haplotypes, with effect estimates from previous genome-wide association studies. GRS2 combined 11 SNPs plus 4 SNPs from the haplotypes with coefficients estimated from these prospective cohorts using 10-fold cross-validation. Scores were added to a model adjusted for classic risk factors comprising the Framingham risk score and 10-year risks were derived.

Results: Both scores improved net reclassification (NRI) over the Framingham score (7.5%, p = 0.017 for GRS1, 6.5%, p = 0.044 for GRS2) but GRS2 also improved discrimination (c-index improvement 1.11%, p = 0.048). Subgroup analysis on men aged 50-59 (436 cases, 603 non-cases) improved net reclassification for GRS1 (13.8%) and GRS2 (12.5%). Net reclassification improvement remained significant for both scores when family history of CHD was added to the baseline model for this male subgroup improving prediction of early onset CHD events.

Conclusions: Genetic risk scores add precision to risk estimates for CHD and improve prediction beyond classic risk factors, particularly for middle aged men.

Rare and common variants in extracellular matrix gene Fibrillin 2 (FBN2) are associated with macular degeneration

Neurodegenerative diseases affecting the macula constitute a major cause of incurable vision loss and exhibit considerable clinical and genetic heterogeneity, from early-onset monogenic disease to multifactorial late-onset age-related macular degeneration (AMD). As part of our continued efforts to define genetic causes of macular degeneration, we performed whole exome sequencing in four individuals of a two-generation family with autosomal dominant maculopathy and identified a rare variant p.Glu1144Lys in Fibrillin 2 (FBN2), a glycoprotein of the elastin-rich extracellular matrix (ECM). Sanger sequencing validated the segregation of this variant in the complete pedigree, including two additional affected and one unaffected individual. Sequencing of 192 maculopathy patients revealed additional rare variants, predicted to disrupt FBN2 function. We then undertook additional studies to explore the relationship of FBN2 to macular disease. We show that FBN2 localizes to Bruch's membrane and its expression appears to be reduced in aging and AMD eyes, prompting us to examine its relationship with AMD. We detect suggestive association of a common FBN2 non-synonymous variant, rs154001 (p.Val965Ile) with AMD in 10,337 cases and 11,174 controls (OR=1.10; p-value=3.79×10(-5)). Thus, it appears that rare and common variants in a single gene - FBN2 - can contribute to Mendelian and complex forms of macular degeneration. Our studies provide genetic evidence for a key role of elastin microfibers and Bruch's membrane in maintaining blood-retina homeostasis and establish the importance of studying orphan diseases for understanding more common clinical phenotypes.