Low expression of the CCL5 gene and low serum concentrations of CCL5 in severe invasive group a streptococcal disease.

PURPOSE: Our objective was to elucidate host dependent factors of disease severity in invasive group A Streptococcal disease (iGAS) using transcriptome profiling of iGAS cases of varying degrees of severity at different timepoints. To our knowledge there are no previous transcriptome studies in iGAS patients. METHODS: We recruited iGAS cases from June 2018 to July 2020. Whole blood samples for transcriptome analysis and serum for biomarker analysis were collected at three timepoints representing the acute (A), the convalescent (B) and the post-infection phase (C). Gene expression was compared against clinical traits and disease course. Serum chemokine ligand 5 (CCL5, an inflammatory cytokine) concentration was also measured. RESULTS: Forty-five patients were enrolled. After disqualifying degraded or impure RNAs we had 34, 31 and 21 subjects at timepoints A, B, and C, respectively. Low expression of the CCL5 gene correlated strongly with severity (death or need for intensive care) at timepoint A (AUC = 0.92), supported by low concentrations of CCL5 in sera. CONCLUSIONS: Low gene expression levels and low serum concentration of CCL5 in the early stages of an iGAS infection were associated with a more severe disease course. CCL5 might have potential as a predictor of disease severity. Low expression of genes of cytotoxic immunity, especially CCL5, and corresponding low serum concentrations of CCL5 associated with a severe disease course, i.e. death, or need for intensive care, in early phase of invasive group A Streptococcal disease.

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.

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.

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.

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.

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.

Gelsolin-derived familial amyloidosis caused by asparagine or tyrosine substitution for aspartic acid at residue 187.

Dominantly inherited familial amyloidosis, Finnish type (FAF) is caused by the accumulation of a 71-amino acid amyloidogenic fragment of mutant gelsolin (GSN). FAF is common in Finland but is very rare elsewhere. In Finland and in two American families, the mutation is a G654A transition leading to an Asp to Asn substitution at residue 187. We found the same mutation in a Dutch family but a Danish FAF family had a G654T mutation, predicting Asp to Tyr at residue 187. We also found the G654T transversion in a Czech family. Using GSN polymorphisms, different haplotypes were found in the Danish and Czech families. We conclude that substitution of the uncharged Asn or Tyr for the acidic Asp at residue 187 creates a conformation that may be preferentially amyloidogenic for GSN.

A susceptibility locus for asthma-related traits on chromosome 7 revealed by genome-wide scan in a founder population.

The genetics of asthma and atopy have been difficult to determine because these diseases are genetically heterogeneous and modified by environment. The pedigrees in our study (n=86) originate in eastern central Finland (Kainuu province). According to census records, this region had only 200 households (2,000 inhabitants) in the mid sixteenth to mid seventeenth centuries. The current population of 100,000 represents the expansion of these founders within the past 400 years. Because this population is relatively homogeneous, we hypothesized that the molecular genetic mechanisms underlying asthma might also have reduced heterogeneity and therefore be easier to dissect than in mixed populations. A recent twin family study supported a strong genetic component for asthma in Finland. We carried out a genome-wide scan for susceptibility loci in asthma in the Kainuu subpopulation. We identified two regions of suggestive linkage and studied them further with higher-density mapping. We obtained evidence for linkage in a 20-cM region of chromosome 7p14-p15 for three phenotypes: asthma, a high level of immunoglobulin E (IgE; atopy) and the combination of the phenotypes. The strongest linkage was seen for high serum IgE (non-parametric linkage (NPL) score 3.9, P=0.0001), exceeding the threshold for genome-wide significance based on simulations. We also observed linkage between this locus and asthma or atopy in two independent data sets.

X-linked anhidrotic (hypohidrotic) ectodermal dysplasia is caused by mutation in a novel transmembrane protein.

Ectodermal dysplasias comprise over 150 syndromes of unknown pathogenesis. X-linked anhidrotic ectodermal dysplasia (EDA) is characterized by abnormal hair, teeth and sweat glands. We now describe the positional cloning of the gene mutated in EDA. Two exons, separated by a 200-kilobase intron, encode a predicted 135-residue transmembrane protein. The gene is disrupted in six patients with X;autosome translocations or submicroscopic deletions; nine patients had point mutations. The gene is expressed in keratinocytes, hair follicles, and sweat glands, and in other adult and fetal tissues. The predicted EDA protein may belong to a novel class with a role in epithelial-mesenchymal signalling.

Mutations of the Down-regulated in adenoma (DRA) gene cause congenital chloride diarrhoea.

A major transport function of the human intestine involves the absorption of chloride in exchange for bicarbonate. We have studied a recessively inherited defect of this exchange, congenital chloride diarrhoea (CLD; MIM 214700). The clinical presentation of CLD is a lifetime, potentially fatal diarrhoea with a high chloride content. The CLD locus was previously mapped to 7q3 adjacent to the cystic fibrosis gene (CFTR). By refined genetic and physical mapping, a cloned gene having anion transport function, Down-regulated in adenoma (DRA), was implicated as a positional and functional candidate for CLD. In this study, we report segregation of two missense mutations, delta V317 and H124L, and one frameshift mutation, 344delT, of DRA in 32 Finnish and four Polish CLD patients. The disease-causing nature of delta V317 is supported by genetic data in relation to the population history of Finland. By mRNA in situ hybridization, we demonstrate that the expression of DRA occurs preferentially in highly differentiated colonic epithelial cells, is unchanged in Finnish CLD patients with delta V317, and is low in undifferentiated (including neoplastic) cells. We conclude that DRA is an intestinal anion transport molecule that causes chloride diarrhoea when mutated.

Juxtaposed regions of extensive and minimal linkage disequilibrium in human Xq25 and Xq28.

Linkage disequilibrium (LD), or the non-random association of alleles, is poorly understood in the human genome. Population genetic theory suggests that LD is determined by the age of the markers, population history, recombination rate, selection and genetic drift. Despite the uncertainties in determining the relative contributions of these factors, some groups have argued that LD is a simple function of distance between markers. Disease-gene mapping studies and a simulation study gave differing predictions on the degree of LD in isolated and general populations. In view of the discrepancies between theory and experimental observations, we constructed a high-density SNP map of the Xq25-Xq28 region and analysed the male genotypes and haplotypes across this region for LD in three populations. The populations included an outbred European sample (CEPH males) and isolated population samples from Finland and Sardinia. We found two extended regions of strong LD bracketed by regions with no evidence for LD in all three samples. Haplotype analysis showed a paucity of haplotypes in regions of strong LD. Our results suggest that, in this region of the X chromosome, LD is not a monotonic function of the distance between markers, but is more a property of the particular location in the human genome.

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.

Interaction between early maternal smoking and variants in TNF and GSTP1 in childhood wheezing.

BACKGROUND: Children exposed to tobacco smoke early in life have a higher risk of wheeze. Individual susceptibility may depend on genetic factors. OBJECTIVE: We studied whether variations in single nucleotide polymorphisms (SNPs) in the TNF, glutathione S transferase P1 (GSTP1) and beta2-adrenoreceptor (ADRB2) genes modify the effect of early maternal smoking on the development of childhood asthma, wheeze and allergic sensitization. METHODS: In the Swedish prospective birth cohort BAMSE (Children, Allergy, Milieu, Stockholm, Epidemiological Survey) (n=4089), data collection included questionnaires to measure tobacco smoke exposure and clinical outcomes up to age 4 and medical examinations with blood sampling for specific IgE measurements and genotyping. We defined early maternal smoking as daily smoking by the mother during pregnancy and/or postnatally. We investigated five TNF, six GSTP1 and three ADRB2 SNPs in 982 selected wheezers and non-wheezers. RESULTS: An interaction with early maternal smoking was found for three TNF SNPs (-857C/T, Intron 1, Intron 3) with respect to early wheeze (up to 2 years of age). For example, the odds ratio (OR) for developing early wheeze related to early maternal smoking was 2.4 [95% confidence interval (CI) 1.6-3.7] in children with a wild-type CC homozygote genotype of the TNF-857 SNP, while no tobacco-related risk was seen in children carrying the rare T allele. A clear dose response was observed in children with the CC genotype, with an OR of 1.3 (95% CI 1.1-1.5) per each additional pack per week smoked by the mother during pregnancy. A suggestive interaction with early maternal smoking was also seen for three GSTP1 SNPs (Intron 5, Intron 6 and Ile105Val) with respect to transient wheeze, but not for ADRB2 and wheeze phenotypes. No effect modifications were observed for allergic sensitization. CONCLUSION: Our results suggest that the risk of early childhood wheeze associated with early maternal smoking may be modified by TNF and GSTP1 polymorphisms.