A novel SERPINA12 variant and first European patients with diffuse palmoplantar keratoderma.

BACKGROUND: Hereditary palmoplantar keratodermas (hPPKs) comprise a heterogeneous group of skin disorders characterized by persistent palmoplantar hyperkeratosis. Loss-of-function variants in a serine peptidase inhibitor, SERPINA12, have recently been implicated in autosomal recessive diffuse hPPK. The disorder appears to share similarities with another hPPK associated with protease overactivity, namely Nagashima-type PPK (NPPK) caused by biallelic variants in SERPINB7. OBJECTIVES: The aim of this study was to enhance the understanding of the clinical and genetic characteristics of serine protease-related hPPKs caused by variants in SERPINA12 and SERPINB7. METHODS: Whole-exome sequencing (WES) was performed for hPPK patients. Haplotype analysis was completed for the patients with identified recessive SERPINA12 variants and their available family members. In addition, the current literature of SERPINA12- and SERPINB7-related hPPKs was summarized. RESULTS: The phenotype of SERPINA12-related hPPK was confirmed by reporting three new SERPINA12 patients, the first of European origin. A novel SERPINA12 c.1100G>A p.(Gly367Glu) missense variant was identified confirming that the variant spectrum of SERPINA12 include both truncating and missense variants. The previously reported SERPINA12 c.631C>T p.(Arg211*) was indicated enriched in the Finnish population due to a plausible founder effect. In addition, SERPINA12 hPPK patients were shown to share a similar phenotype to patients with recessive variants in SERPINB7. The shared phenotype included diffuse transgradient PPK since birth or early childhood and frequent palmoplantar hyperhidrosis, aquagenic whitening and additional hyperkeratotic lesions in non-palmoplantar areas. SERPINA12 and SERPINB7 hPPK patients cannot be distinguished without genetic analysis. CONCLUSIONS: Recessive variants in SERPINA12 and SERPINB7 leading to protease overactivity and hPPK produce a similar phenotype, indistinguishable without genetic analysis. SERPINA12 variants should be assessed also in non-Asian patients with diffuse transgradient PPK. Understanding the role of serine protease inhibitors will provide insights into the complex proteolytic network in epidermal homeostasis.

A novel desmoplakin mutation causes dilated cardiomyopathy with palmoplantar keratoderma as an early clinical sign.

BACKGROUND: PPKs represent a heterogeneous group of disorders with hyperkeratosis of palmar and/or plantar skin. PPK, hair shaft abnormalities, cardiomyopathy and arrhythmias can be caused by mutations in desmosomal genes, e.g. desmoplakin (DSP). PPK should trigger genetic testing to reveal mutations with possible related cardiac disease. OBJECTIVES: To report a large multigenerational family with a novel DSP mutation associated with early-onset PPK and adult-onset cardiomyopathy and arrhythmias. METHODS: A custom-designed in-house panel of 35 PPK related genes was used to screen mutations in the index patient with focal PPK. The identified DSP mutation was verified by Sanger sequencing. DNA samples from 20 members of the large multigenerational family were sequenced for the DSP mutation. Medical records were reviewed. Clinical dermatological evaluation was performed, including light microscopy of hair samples. Cardiac evaluation included clinical examination, echocardiography, cardiac magnetic resonance imaging (CMR), electrocardiogram (ECG), Holter monitoring and laboratory tests. RESULTS: We identified a novel autosomal dominant truncating DSP c.2493delA p.(Glu831Aspfs*33) mutation associated with dilated cardiomyopathy (DCM) with arrhythmia susceptibility and focal PPK as an early cutaneous sign. The mutation was found in nine affected family members, but not in any unaffected members. Onset of dermatological findings preceded cardiac symptoms which were variable and occurred at adult age. CONCLUSIONS: We report a novel truncating DSP mutation causing focal PPK with varying severity and left ventricular dilatation and ventricular extrasystoles. This finding emphasizes the importance of genetic diagnosis in patients with PPK for clinical counselling and management of cardiomyopathies and arrhythmias.

Founder effects facilitate the use of a genotyping-based approach to molecular diagnosis in Swedish patients with familial hypercholesterolaemia.

AIM: To investigate whether genotyping could be used as a cost-effective screening step, preceding next-generation sequencing (NGS), in molecular diagnosis of familial hypercholesterolaemia (FH) in Swedish patients. METHODS AND RESULTS: Three hundred patients of Swedish origin with clinical suspicion of heterozygous FH were analysed using a specific array genotyping panel embedding 112 FH-causing mutations in the LDLR, APOB and PCSK9 genes. The mutations had been selected from previous reports on FH patients in Scandinavia and Finland. Mutation-negative cases were further analysed by NGS. In 181 patients with probable or definite FH using the Dutch lipid clinics network (DLCN) criteria (score ≥ 6), a causative mutation was identified in 116 (64%). Of these, 94 (81%) were detected by genotyping. Ten mutations accounted for more than 50% of the positive cases, with APOB c.10580G>A being the most common. Mutations in LDLR predominated, with (c.2311+1_2312-1)(2514)del (FH Helsinki) and c.259T>G having the highest frequency. Two novel LDLR mutations were identified. In patients with DLCN score < 6, mutation detection rate was significantly higher at younger age. CONCLUSION: A limited number of mutations explain a major fraction of FH cases in Sweden. Combination of selective genotyping and NGS facilitates the clinical challenge of cost-effective genetic screening in suspected FH. The frequency of APOB c.10580G>A was higher than previously reported in Sweden. The lack of demonstrable mutations in the LDLR, APOB and PCSK9 genes in ~1/3 of patients with probable FH strongly suggests that additional genetic mechanisms are to be found in phenotypic FH.

Hereditary palmoplantar keratoderma - phenotypes and mutations in 64 patients.

BACKGROUND: Hereditary palmoplantar keratodermas (PPK) represent a heterogeneous group of rare skin disorders with epidermal hyperkeratosis of the palms and soles, with occasional additional manifestations in other tissues. Mutations in at least 69 genes have been implicated in PPK, but further novel candidate genes and mutations are still to be found. OBJECTIVES: To identify mutations underlying PPK in a cohort of 64 patients. METHODS: DNA of 48 patients was analysed on a custom-designed in-house panel for 35 PPK genes, and 16 patients were investigated by a diagnostic genetic laboratory either by whole-exome sequencing, gene panels or targeted single-gene sequencing. RESULTS: Of the 64 PPK patients, 32 had diffuse (50%), 19 focal (30%) and 13 punctate (20%) PPK. None had striate PPK. Pathogenic mutations in altogether five genes were identified in 31 of 64 (48%) patients, the majority (22/31) with diffuse PPK. Of them, 11 had a mutation in AQP5, five in SERPINB7, four in KRT9 and two in SLURP1. AAGAB mutations were found in nine punctate PPK patients. New mutations were identified in KRT9 and AAGAB. No pathogenic mutations were detected in focal PPK. Variants of uncertain significance (VUS) in PPK-associated and other genes were observed in 21 patients that might explain their PPK. No suggestive pathogenic variants were found for 12 patients. CONCLUSIONS: Diffuse PPK was the most common (50%) and striate PPK was not observed. We identified pathogenic mutations in 48% of our PPK patients, mainly in five genes: AQP5, AAGAB, KRT9, SERPINB7 and SLURP1.

Children at risk for dyslexia show deficient left-hemispheric memory representations for new spoken word forms.

Developmental dyslexia is a specific learning disorder with impairments in reading and spelling acquisition. Apart from literacy problems, dyslexics show inefficient speech encoding and deficient novel word learning, with underlying problems in phonological processing and learning. These problems have been suggested to be related to deficient specialization of the left hemisphere for language processing. To examine this possibility, we tracked with magnetoencephalography (MEG) the activation of the bilateral temporal cortices during formation of neural memory traces for new spoken word forms in 7-8-year-old children with high familial dyslexia risk and in controls. The at-risk children improved equally to their peers in overt repetition of recurring new word forms, but were poorer in explicit recognition of the recurring word forms. Both groups showed reduced activation for the recurring word forms 400-1200 ms after word onset in the right auditory cortex, replicating the results of our previous study on typically developing children (Nora et al., 2017, Children show right-lateralized effects of spoken word-form learning. PLoS ONE 12(2): e0171034). However, only the control group consistently showed a similar reduction of activation for recurring word forms in the left temporal areas. The results highlight the importance of left-hemispheric phonological processing for efficient phonological representations and its disruption in dyslexia.

Pool-seq driven proteogenomic database for Group G Streptococcus.

Proteogenomic databases use genomic and transcriptomic information for improved identification of peptides and proteins from mass spectrometry analyses. One application of such databases is in the discovery of variants/mutations. In this study, we created a proteogenomic database that contained sequences with variants derived from Pooled sequencing experiments (137 Group G Streptococcus strains sequenced in 3 pools) and used tandem mass spectrometry (MS/MS) to analyse eight protein samples from randomly selected strains sequenced in the pools. Using the proteogenomic variant database, we identified 385 variant peptides from the eight samples, none of which could be identified from the single genome conventional database utilized, while 71.2% and 93.5% of them were identified from the databases that contained 4 complete genomes and 26 assemblies, respectively. The proteogenomic variant databases exhibited the same properties as the conventional databases in terms of the Andromeda score distributions and the posterior error probability (PEP) values of the identified peptides. SIGNIFICANCE: For bacterial populations, such as Group G Streptococcus (GGS), with substantial intra-species diversity, simultaneous sequencing of large numbers of strains and generation of proteogenomic databases from those aids in improving the discovery of peptides in mass spectrometric analyses. Therefore, generation of proteogenomic variant protein databases from Pooled sequencing experiments can be a cost-effective method to complement conventional databases and discover subtle strain wise differences.

Enrichment of rare copy number variation in children with developmental language disorder.

Developmental language disorder (DLD) is a common neurodevelopmental disorder with largely unknown etiology. Rare copy number variants (CNVs) have been implicated in the genetic architecture of other neurodevelopmental disorders (NDDs), which have led to clinical genetic testing recommendations for these disorders; however, the evidence is still lacking for DLD. We analyzed rare and de novo CNVs in 58 probands with severe DLD, their 159 family members and 76 Swedish typically developing children using high-resolution microarray. DLD probands had larger rare CNVs as measured by total length (P = .05), and average length (P = .04). In addition, the rate of rare CNVs overlapping coding genes was increased (P = .03 and P = .01) and in average more genes were affected (P = .006 and P = .03) in the probands and their siblings, respectively. De novo CNVs were found in 4.8% DLD probands (2/42) and 2.4% (1/42) siblings. Clinically significant CNVs or chromosomal anomalies were found in 6.9% (4/58) of the probands of which 2 carried 16p11.2 deletions. We provide further evidence that rare CNVs contribute to the etiology of DLD in loci that overlap with other NDDs. Based on our results and earlier literature, families with DLD should be offered molecular genetic testing as a routine in their clinical follow-up.

Single-cell transcriptome analysis of endometrial tissue.

STUDY QUESTION: How can we study the full transcriptome of endometrial stromal and epithelial cells at the single-cell level? SUMMARY ANSWER: By compiling and developing novel analytical tools for biopsy, tissue cryopreservation and disaggregation, single-cell sorting, library preparation, RNA sequencing (RNA-seq) and statistical data analysis. WHAT IS KNOWN ALREADY: Although single-cell transcriptome analyses from various biopsied tissues have been published recently, corresponding protocols for human endometrium have not been described. STUDY DESIGN, SIZE, DURATION: The frozen-thawed endometrial biopsies were fluorescence-activated cell sorted (FACS) to distinguish CD13-positive stromal and CD9-positive epithelial cells and single-cell transcriptome analysis performed from biopsied tissues without culturing the cells. We studied gene transcription, applying a modern and efficient RNA-seq protocol. In parallel, endometrial stromal cells were cultured and global expression profiles were compared with uncultured cells. PARTICIPANTS/MATERIALS, SETTING, METHODS: For method validation, we used two endometrial biopsies, one from mid-secretory phase (Day 21, LH+8) and another from late-secretory phase (Day 25). The samples underwent single-cell FACS sorting, single-cell RNA-seq library preparation and Illumina sequencing. MAIN RESULTS AND THE ROLE OF CHANCE: Here we present a complete pipeline for single-cell gene-expression studies, from clinical sampling to statistical data analysis. Tissue manipulation, starting from disaggregation and cell-type-specific labelling and ending with single-cell automated sorting, is managed within 90 min at low temperature to minimize changes in the gene expression profile. The single living stromal and epithelial cells were sorted using CD13- and CD9-specific antibodies, respectively. Of the 8622 detected genes, 2661 were more active in cultured stromal cells than in biopsy cells. In the comparison of biopsy versus cultured cells, 5603 commonly expressed genes were detected, with 241 significantly differentially expressed genes. Of these, 231 genes were up- and 10 down-regulated in cultured cells, respectively. In addition, we performed a gene ontology analysis of the differentially expressed genes and found that these genes are mainly related to cell cycle, translational processes and metabolism. LIMITATIONS, REASONS FOR CAUTION: Although CD9-positive single epithelial cells sorting was successfully established in our laboratory, the amount of transcriptome data per individual epithelial cell was low, complicating further analysis. This step most likely failed due to the high dose of RNases that are released by the cells' natural processes, or due to rapid turnaround time or the apoptotic conditions in freezing- or single-cell solutions. Since only the cells from the late-secretory phase were subject to more focused analysis, further studies including larger sample size from the different time-points of the natural menstrual cycle are needed. The methodology also needs further optimization to examine different cell types at high quality. WIDER IMPLICATIONS OF THE FINDINGS: The symbiosis between clinical biopsy and the sophisticated laboratory and bioinformatic protocols described here brings together clinical diagnostic needs and modern laboratory and bioinformatic solutions, enabling us to implement a precise analytical toolbox for studying the endometrial tissue even at the single-cell level.

Evidence of streptococcal origin of acute non-necrotising cellulitis: a serological study.

Bacteriological diagnosis is rarely achieved in acute cellulitis. Beta-haemolytic streptococci and Staphylococcus aureus are considered the main pathogens. The role of the latter is, however, unclear in cases of non-suppurative cellulitis. We conducted a serological study to investigate the bacterial aetiology of acute non-necrotising cellulitis. Anti-streptolysin O (ASO), anti-deoxyribonuclease B (ADN) and anti-staphylolysin (ASTA) titres were measured from acute and convalescent phase sera of 77 patients hospitalised because of acute bacterial non-necrotising cellulitis and from the serum samples of 89 control subjects matched for age and sex. Antibiotic treatment decisions were also reviewed. Streptococcal serology was positive in 53 (69%) of the 77 cases. Furthermore, ten cases without serological evidence of streptococcal infection were successfully treated with penicillin. Positive ASO and ADN titres were detected in ten (11%) and three (3%) of the 89 controls, respectively, and ASTA was elevated in three patients and 11 controls. Our findings suggest that acute non-necrotising cellulitis without pus formation is mostly of streptococcal origin and that penicillin can be used as the first-line therapy for most patients.

NPSR1 polymorphisms influence recurrent abdominal pain in children: a population-based study.

BACKGROUND: Recurrent abdominal pain (RAP) occurs frequently among children and is one of the cardinal symptoms of functional gastrointestinal disorders (FGID). The mechanisms of visceral pain and RAP are not fully understood. A heritable component has been demonstrated and a few candidate genes proposed. NPSR1 encodes the receptor for neuropeptide S (NPS) and NPS-NPSR1 signaling is involved in anxiety, inflammation, and nociception. NPSR1 polymorphisms are associated with asthma and chronic inflammatory diseases, but also with IBS-related intermediate phenotypes such as colonic transit time and rectal sensory ratings. Here, we sought to determine whether genetic variability in the NPSR1 gene influences the presence of RAP in children. METHODS: Twenty-eight single-nucleotide polymorphisms (SNPs) in the NPSR1 gene region were successfully genotyped in 1744 children from the Swedish birth cohort BAMSE. Questionnaire information was used to define RAP as episodes of abdominal pain occurring at least once a month in 12-year-olds. KEY RESULTS: The prevalence of RAP was 9% in BAMSE. Association with RAP was observed for seven NPSR1 SNPs, five of which withstood false discovery rate (FDR) correction for multiple testing (best p = 0.00054, OR: 1.55 for SNP rs2530566). The associated SNPs all map in a putative regulatory region upstream NPSR1, where they may exert their genetic effects through the modulation of gene expression. CONCLUSIONS & INFERENCES: Genetic variation at the NPSR1 locus impacts children's predisposition to RAP episodes in a Swedish population.

Neuropeptide S receptor 1 (NPSR1) activates cancer-related pathways and is widely expressed in neuroendocrine tumors.

Neuroendocrine tumors (NETs) arise from disseminated neuroendocrine cells and express general and specific neuroendocrine markers. Neuropeptide S receptor 1 (NPSR1) is expressed in neuroendocrine cells and its ligand neuropeptide S (NPS) affects cell proliferation. Our aim was to study whether NPS/NPSR1 could be used as a biomarker for neuroendocrine neoplasms and to identify the gene pathways affected by NPS/NPSR1. We collected a cohort of NETs comprised of 91 samples from endocrine glands, digestive tract, skin, and lung. Tumor type was validated by immunostaining of chromogranin-A and synaptophysin expression and tumor grade was analyzed by Ki-67 proliferation index. NPS and NPSR1 expression was quantified by immunohistochemistry using polyclonal antibodies against NPS and monoclonal antibodies against the amino-terminus and carboxy-terminus of NPSR1 isoform A (NPSR1-A). The effects of NPS on downstream signaling were studied in a human SH-SY5Y neuroblastoma cell line which overexpresses NPSR1-A and is of neuroendocrine origin. NPSR1 and NPS were expressed in most NET tissues, with the exception of adrenal pheochromocytomas in which NPS/NPSR1 immunoreactivity was very low. Transcriptome analysis of NPSR1-A overexpressing cells revealed that mitogen-activated protein kinase (MAPK) pathways, circadian activity, focal adhesion, transforming growth factor beta, and cytokine-cytokine interactions were the most altered gene pathways after NPS stimulation. Our results show that NETs are a source of NPS and NPSR1, and that NPS affects cancer-related pathways.

Association and Mutation Analyses of the IRF6 Gene in Families With Nonsyndromic and Syndromic Cleft Lip and/or Cleft Palate.

OBJECTIVES: (1) To detect interferon regulatory factor 6 gene (IRF6) mutations in newly recruited Van der Woude syndrome (VWS) and popliteal pterygium syndrome (PPS) families. (2) To test for association, in nonsyndromic cleft lip and/or cleft palate (NSCL/P) and in VWS/PPS families, the single nucleotide polymorphism (SNP) rs642961, from the IRF6 enhancer AP-2α region, alone or as haplotype with rs2235371, a coding SNP (Val274Ile). DESIGN: IRF6 mutation screening was performed by direct sequencing and genotyping of rs642961 and rs2235371 by TaqMan technology. PATIENTS: Seventy-one Swedish NSCL/P families, 24 Finnish cleft palate (CP) families, and 24 VWS/PPS families (seven newly recruited) were studied. RESULTS: Allelic and genotypic frequencies in each phenotype were compared to those of the controls, and no significant difference could be observed. IRF6 gene mutation was detected in six of the seven new VWS/PPS families. Association analysis of the entire VWS/PPS sample set revealed the A allele from rs642961 to be a risk allele. Significant association was detected in the Swedish CP subset of our NSCL/P collection where the G-C haplotype for rs642961-rs2235371 were at risk (P = .013). CONCLUSIONS: Our results do not support the previously reported association between the A allele of rs642961 and the NSCL phenotype. However, in the VWS/PPS families, the A allele was a risk allele and was, in a large majority (>80%), transmitted on the same chromosome as the IRF6 mutation.

Introduction of complementary foods in infancy and atopic sensitization at the age of 5 years: timing and food diversity in a Finnish birth cohort.

OBJECTIVE: To study the associations between timing and diversity of introduction of complementary foods during infancy and atopic sensitization in 5-year-old children. METHODS: In the Finnish DIPP (type 1 diabetes prediction and prevention) birth cohort (n = 3781), data on the timing of infant feeding were collected up to the age of 2 years and serum IgE antibodies toward four food and four inhalant allergens measured at the age of 5 years. Logistic regression was used for the analyses. RESULTS: Median duration of exclusive and total breastfeeding was 1.4 (interquartile range: 0.2-3.5) and 7.0 (4.0-11.0) months, respectively. When all the foods were studied together and adjusted for confounders, short duration of breastfeeding decreased the risk of sensitization to birch allergen; introduction of oats <5.1 months and barley <5.5 months decreased the risk of sensitization to wheat and egg allergens, and oats additionally associated with milk, timothy grass, and birch allergens. Introduction of rye <7.0 months decreased the risk of sensitization to birch allergen. Introduction of fish <6 months and egg ≤11 months decreased the risk of sensitization to all the specific allergens studied. The introduction of <3 food items at 3 months was associated with sensitization to wheat, timothy grass, and birch allergens; the introduction of 1-2 food items at 4 months and ≤4 food items at 6 months was associated with all endpoints, but house dust mite. These results were particularly evident among high-risk children when the results were stratified by atopic history, indicating the potential for reverse causality. CONCLUSIONS: The introduction of complementary foods was consecutively done, and with respect to the timing of each food, early introduction of complementary foods may protect against atopic sensitization in childhood, particularly among high-risk children. Less food diversity as already at 3 months of age may increase the risk of atopic sensitization.

Recurrent cellulitis with benzathine penicillin prophylaxis is associated with diabetes and psoriasis.

Risk factors for recurrent cellulitis were assessed in a case-control study including 398 patients receiving prophylactic treatment with benzathine penicillin and 8,005 controls derived from a national population-based health survey. In the multivariate analysis, psoriasis [odds ratio (OR) 3.69], other chronic dermatoses (OR 4.14), diabetes (OR 1.65), increasing body mass index (OR 1.17), increasing age (OR 1.06) and history of previous tonsillectomy (OR 6.82) were independently associated with recurrent cellulitis. Forty percent of the patients reported a cellulitis recurrence, despite ongoing benzathine penicillin prophylaxis. The role of previous tonsillectomy in recurrent cellulitis needs further evaluation.

Working memory brain activity and capacity link MAOA polymorphism to aggressive behavior during development.

A developmental increase in working memory capacity is an important part of cognitive development, and low working memory (WM) capacity is a risk factor for developing psychopathology. Brain activity represents a promising endophenotype for linking genes to behavior and for improving our understanding of the neurobiology of WM development. We investigated gene-brain-behavior relationships by focusing on 18 single-nucleotide polymorphisms (SNPs) located in six dopaminergic candidate genes (COMT, SLC6A3/DAT1, DBH, DRD4, DRD5, MAOA). Visuospatial WM (VSWM) brain activity, measured with functional magnetic resonance imaging, and VSWM capacity were assessed in a longitudinal study of typically developing children and adolescents. Behavioral problems were evaluated using the Child Behavior Checklist (CBCL). One SNP (rs6609257), located ~6.6 kb downstream of the monoamine oxidase A gene (MAOA) on human chromosome X, significantly affected brain activity in a network of frontal, parietal and occipital regions. Increased activity in this network, but not in caudate nucleus or anterior prefrontal regions, was correlated with VSWM capacity, which in turn predicted externalizing (aggressive/oppositional) symptoms, with higher WM capacity associated with fewer externalizing symptoms. There were no direct significant correlations between rs6609257 and behavioral symptoms. These results suggest a mediating role of WM brain activity and capacity in linking the MAOA gene to aggressive behavior during development.

OS077. The chromosome 2q22 preeclampsia susceptibility locus reveals shared novel risk factors for CVD.

INTRODUCTION: We have previously localized a preeclampsia susceptibility locus on chromosome 2q22 in 34 Australian and New Zealand (AUS/NZL) families. Using an extended number of AUS/NZL families (n=74) we have now performed a comprehensive molecular genetics dissection of this locus. OBJECTIVES: Identify causal genetic risk factors for preeclampsia at the 2q22 risk locus. METHODS: To prioritize positional candidate genes for analysis we used a combination of bioinformatics, SNPing, whole-genome transcriptional profiling and proximity to the peak linkage signal. Prioritized genes were earmarked for exon-centric re-sequencing in 48 founder individuals from the 74 AUS/NZL families. All identified sequence variants were genotyped back in this extended familial cohort. Variants showing the strongest genetic association were genotyped in independent case-control cohorts from Australia (n=1095), Norway (n=3397) and Finland (n=1519), and in a large cohort of Mexican American families rich in quantitative cardiovascular disease (CVD) risk traits. RESULTS: We interrogated 1598 variants from 52 genes and identified four independent SNPs to be significantly associated with preeclampsia susceptibility in the 74 AUS/NZL families. These four SNPs reside in four novel preeclampsia candidate genes: LCT (rs2322659, p=0.002), LRP1B (rs35821928, p=0.0001), RND3 (rs115015150, p=0.002) and GCA (rs17783344, p=0.002). We could only replicate the LCT SNP association in the Australian case-control population (p=0.04, combined p=0.001). These four SNPs are however, significantly associated with several quantitative CVD risk traits such as oxidative stress indicators, inflammatory biomarkers and obesity risk factors. CONCLUSION: Previous independent studies have reported significant genetic associations with total cholesterol levels and obesity risk factors for variants within LCT and LRP1B, respectively. RND3 inhibits the biological activity of a downstream effector protein, ROCK, which is known to affect endothelial dysfunction, inflammation, oxidative stress and vascular re-modeling. Grancalcin (GCA) is known to impact the adhesive properties of fibronectin, a marker for endothelial vascular injury. To our knowledge, data from the current study present for the first time empirical evidence of possible shared genetic risk factors underlying both preeclampsia and other CVD-related traits.

PP009. A follow-up study of Finnish pre-eclampsia families identifies a new fetal susceptibility locus on chromosome 18.

INTRODUCTION: According to the epidemiological research both maternal and fetal genes influence in predisposition to pre-eclampsia (PE). We have previously detected linkage signals in Finnish families on chromosomes 2p25, 4q32, and 9p13 using maternal phenotypes. OBJECTIVES: Our aim was to perform a follow-up linkage analysis using updated maternal phenotypes and an unprecedented linkage analysis using fetal phenotypes. METHODS: We performed a non-parametric linkage analysis using the same sample set and microsatellite markers as reported in the original linkage study (Laivuori et al., [1]). Markers genotyped were available from 237 individuals in 15 Finnish families including 72 affected mothers (pregnancy complicated by PE n=54, eclampsia n=1, or gestational hypertension [GHT] n=17), and 49 affected fetuses (born from a pregnancy complicated by PE n=45, or GHT n=4). MERLIN software (Abecasis et al., 2002) was used for sample and marker quality control and linkage analysis. Results from this study were compared against the original results obtained by using GENEHUNTER 2.1 software. RESULTS: The maximum nonparametric linkage (NPL) scores on chromosome 2 were at 21.70cM near marker D2S168 using maternal and fetal phenotypes (NPL score 3.79, p=0.00008, and NPL score 2.95, p=0.002, respectively). On chromosome 4 the highest peak was at 158.20 cM near marker D4S413 using maternal phenotypes (NPL score 3.13 p=0.0009), and at 109.60 cM near marker D4S1572 using fetal phenotypes (NPL score 2.50, p=0.006). On chromosome 9 the highest peaks using maternal phenotypes were at 38.90cM near marker D9S169 (NPL=3.76, p=0.00008), and at 120.80 cM near marker D9S1811 (NPL=2.74, p=0.003). The maximum peak on chromosome 9 using fetal phenotypes was found at 59.20cM near marker D9S175 (NPL=2.69, p=0.004). We found a suggestive linkage on chromosome 18 at 86.80cM near marker D18S64 using fetal phenotypes (NPL score of 2.51, p=0.006), but the highest peak using maternal phenotypes did not reach significance. CONCLUSION: In this follow-up study we have confirmed the linkage signals identified in the original linkage analysis using maternal phenotypes. Linkage to chromosome 2 was also supported by analysis using fetal phenotypes. Chromosome 18 may harbour a new fetal susceptibility locus for PE.

Genome-wide analysis of extended pedigrees confirms IL2-IL21 linkage and shows additional regions of interest potentially influencing coeliac disease risk.

Coeliac disease is a chronic inflammatory condition of the small intestine, triggered by dietary exposure to gluten in genetically susceptible individuals. Risk alleles at HLA-DQA1 and HLA-DQB1 are necessary for disease development, but are alone not sufficient for disease onset. We aimed to identify novel loci underlying susceptibility to coeliac disease through the use of extended Finnish and Hungarian families with multiple affected individuals. An initial whole-genome linkage approach yielded several loci that were followed up further using the Immunochip custom array. Loci with a parametric logarithm of odds (LOD) score of >1.3 were identified at 4q, 6p [human leukocyte antigen (HLA) region], 6q, 7p, 17p, 17q and at 22p. The 4q and 6q loci have been identified previously in coeliac disease risk, whereas follow-up analyses indicate that the 17p and 22p loci may be novel risk loci for coeliac disease. These loci harbour previously described risk variants for other autoimmune diseases, but their segregation patterns do not explain the linkage to coeliac disease. We followed up the linkage to the 4q region, containing the previously described interleukin (IL)2 and IL21 genes. The risk variants at 4q in the studied pedigrees are most likely distinct from previously described risk variants, indicating that the observed linkage may be due to rare high-risk variants of still unknown nature. The importance of this locus to coeliac disease risk was further shown by the finding that serum levels of IL21 were elevated in both untreated and treated coeliac patients compared to controls.

NANOG priming before full reprogramming may generate germ cell tumours.

Reprogramming somatic cells into a pluripotent state brings patient-tailored, ethical controversy-free cellular therapy closer to reality. However, stem cells and cancer cells share many common characteristics; therefore, it is crucial to be able to discriminate between them. We generated two induced pluripotent stem cell (iPSC) lines, with NANOG pre-transduction followed by OCT3/4, SOX2, and LIN28 overexpression. One of the cell lines, CHiPS W, showed normal pluripotent stem cell characteristics, while the other, CHiPS A, though expressing pluripotency markers, failed to differentiate and gave rise to germ cell-like tumours in vivo. Comparative genomic hybridisation analysis of the generated iPS lines revealed that they were genetically more stable than human embryonic stem cell counterparts. This analysis proved to be predictive for the differentiation potential of analysed cells. Moreover, the CHiPS A line expressed a lower ratio of p53/p21 when compared to CHiPS W. NANOG pre-induction followed by OCT3/4, SOX2, MYC, and KLF4 induction resulted in the same tumour-inducing phenotype. These results underline the importance of a re-examination of the role of NANOG during reprogramming. Moreover, this reprogramming method may provide insights into primordial cell tumour formation and cancer stem cell transformation.