Thore Egeland

Analysis of linkage and linkage disequilibrium for eight X-STR markers

X-chromosomal short tandem repeats (X-STR) have proven to be informative and useful in complex relationship testing. The main feature of X-STR markers, compared to autosomal forensic markers, is that all loci are located on the same chromosome. Thus, linkage and linkage disequilibrium may occur. The aim of this work was to study population genetic parameters of eight X-STR markers, located in four linkage groups. We present haplotype frequencies, based on 718 Swedish males, for the four linkage groups included in the Argus X-8 kit. Forensic efficiency parameters have been calculated as well as the allelic association between the tested markers for detection of linkage disequilibrium. To study the occurrences of recombination between the loci, both Swedish and Somali families were typed. A mathematical model for the estimation of recombination frequencies is presented and applied on the family samples. Our study showed that the tested markers all have highly informative forensic values and that there is a significant degree of linkage disequilibrium between the STR markers within the four linkage groups. Furthermore, based on the tested families, we also demonstrated that two of the linkage groups are partially linked. A consequence of these findings is that both linkage and linkage disequilibrium should be accounted for when producing likelihood ratios in relationship testing with X-STR markers.

Natural killer (NK) cell activity of peripheral blood, synovial fluid, and synovial tissue lymphocytes from patients with rheumatoid arthritis and juvenile rheumatoid arthritis.

Natural killer (NK) cell activity was investigated in peripheral blood, synovial fluid, and synovial tissue lymphocytes from patients with rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA). Unfractionated lymphocytes, T lymphocytes, and non-T lymphocytes from the 3 compartments of JRA patients had reduced activity compared with that of normal peripheral blood lymphocytes (with p values usually between 0.05 and 0.1). Unfractionated synovial tissue lymphocytes of RA patients also showed reduced cytotoxicity (0.05 less than p less than 0.1), whereas peripheral blood lymphocytes exerted normal NK cell activity. The NK activity was exerted by cells both with and without Fc gamma receptors. The highest cytotoxicity was observed in Fc gamma receptor-positive cells, both in peripheral blood and synovial fluid, since more than 70% reduction in NK activity was found after depletion of Fc gamma receptor-positive cells. No evidence of lymphocytotoxic antibodies or other factors with influence on NK cells was observed in the patients sera.

A TLR2 polymorphism is associated with type 1 diabetes and allergic asthma

Type 1 diabetes (T1D) and allergic asthma are immune-mediated diseases. Pattern recognition receptors are proteins expressed by cells in the immune system to identify microbial pathogens and endogenous ligands. Toll-like receptors (TLRs) and CD14 are members of this family and could represent a molecular link between microbial infections and immune-mediated diseases. Diverging hypotheses regarding whether there exists a common or inverse genetic etiology behind these immune-mediated diseases have been presented. We aimed to test whether there exist common or inverse associations between polymorphisms in the pattern recognition receptors TLR2, TLR4 and CD14 and T1D and allergic asthma. Eighteen single nucleotide polymorphisms (SNPs) were genotyped in TLR2 (2), TLR4 (12) and CD14 (4) in 700 T1D children, 357 nuclear families with T1D children and 796 children from the ‘Environment and Childhood Asthma’ study. Allele and haplotype frequencies were analyzed in relation to diseases and in addition transmission disequilibrium test analyses were performed in the family material. Both T1D and allergic asthma were significantly associated with the TLR2 rs3804100 T allele and further associated with the haplotype including this SNP, possibly representing a susceptibility locus common for the two diseases. Neither TLR4 nor CD14 were associated with T1D or allergic asthma.

HLA Dr‐Dq haplotypes and the TNFA‐308 polymorphism: associations with asthma and allergy

Background:u2002 The HLA (human leukocyte antigen) class II genes DQB1 and DRB1 and the Tumor Necrosis Factor α gene (TNFA) within the HLA complex (chromosome 6p21) have been associated with asthma and allergy. Due to the strong linkage disequilibrium characterizing this complex and the multiple asthma/allergy expressions, we aimed to determine which of these genes were primarily involved in specific asthma/allergy traits.

Eosinophil cationic protein (ECP) polymorphisms and association with asthma, s-ECP levels and related phenotypes

Background:u2002 Eosinophil cationic protein (ECP) is a potent cytotoxic secretory protein with bactericidal and antiviral properties. ECP is released by activated eosinophils and regarded as a marker of eosinophilic inflammation. High levels of ECP have been reported in cases of active asthma and other allergic diseases. This study aimed to assess whether three single‐nucleotide polymorphisms (SNPs) in the ECP gene (RNASE3) on chromosome 14 q24–q31 or their haplotypes are associated with asthma, allergy, or related phenotypes.

Fibromyalgia patients' communication of cues and concerns: interaction analysis of pain clinic consultations.

ObjectivesClinicians recognition of patients concerns is an important component of effective treatment and care. During a consultation, patients often do not express their concerns directly, but rather present them indirectly as hints or cues. The aim of this study was to explore the types of concerns and cues patients expressed in an initial consultation with a nurse at a pain clinic, how and who initiated these cues and concerns, and predictors of these expressions. MethodsInitial consultations between patients with fibromyalgia [n=58, 85% female, duration 30 minutes, mean age 47.8 y (SD 10.7)] and clinical nurse specialists (n=5) were videotaped. Patients cues and concerns were coded using the Verona Coding Definitions of Emotional Sequences. Nurses responses to patients cues and concerns were evaluated using the Hierarchical Coding Scheme of Comforting Strategies. In addition, pain intensity and duration, overall evaluation of health, affect at the start of the consultation, and psychological distress were evaluated. ResultsPatients expressed more cues than concerns, mostly about pain, interpersonal relationships, and/or emotional reactions. Both the lack of empathic responding and unspecific empathic responding were associated with the expression of an increased number of cues in the consultation, whereas higher evaluation of health was associated with less cues. More concerns were expressed by patients when nurses exhibited a high level of empathic responding and when the patient entered the consultation with a higher level of negative effect. DiscussionFindings from this study highlight the importance of a patient centered communication style to facilitate the expression of cues and concerns.

Original article: Eosinophil cationic protein (ECP) polymorphisms and association with asthma, s-ECP levels and related phenotypes

Background:u2002 Eosinophil cationic protein (ECP) is a potent cytotoxic secretory protein with bactericidal and antiviral properties. ECP is released by activated eosinophils and regarded as a marker of eosinophilic inflammation. High levels of ECP have been reported in cases of active asthma and other allergic diseases. This study aimed to assess whether three single‐nucleotide polymorphisms (SNPs) in the ECP gene (RNASE3) on chromosome 14 q24–q31 or their haplotypes are associated with asthma, allergy, or related phenotypes.

FTO Genotype and Weight Gain in Obese and Normal Weight Adults From a Norwegian Population Based Cohort (the HUNT Study)

The fat mass and obesity associated gene ( FTO) is associated with bodyweight and obesity. The aim of this study was to investigate if FTO genotype affects weight gain in adulthood. We investigated the weight development over a period of 11 years in a case-control study, consisting of 1,632 cases (BMI≥35 kg/m (2)) and 3,379 normal weight controls (BMI 20-24.9 kg/m (2)) from a Norwegian population based cohort, the HUNT study. Subjects were aged 20-80 at baseline, 25% men and 75% women. FTO genotype was assessed by genotyping of the SNP rs1421085. A strong association between FTO and obesity was found, consistent with an additive gene effect. Cases had an average weight gain of 11.1 kg, whereas controls had an average weight gain of 1.4 kg. Genotype was neither associated with weight gain in obese, nor controls. Cases had an average weight gain of 10.7 kg for individuals with zero risk alleles, 11.3 for one risk allele and 11.1 kg for two risk alleles. Controls had an average weight gain of 1.4 kg, 1.4 and 1.3 for the respective genotypes. In conclusion, FTO was associated with obesity, but not with weight gain in adults during 11 years of follow-up.

Genome-wide Linkage Analysis with Clustered SNP Markers

Single nucleotide polymorphisms (SNPs) have recently replaced microsatellites as the genetic markers of choice in linkage analysis, primarily because they are more abundant and the genotypes more amenable for automatic calling. One of the most recently launched linkage mapping sets (LMS) is the Applied Biosystems Human LMS 4K, which is a genome-wide linkage set based on the SNPlex™ technology and the use of clustered SNPs. In this article the authors report on their experience with this set and the associated genotyping software GeneMapper® version 4.0, which they have used for linkage analyses in 17 moderate to large families with assumed monogenic disease. For comparison of methods, they also performed a genome-wide linkage analysis in 1 of the 17 families using the Affymetrix GeneChip® Human Mapping 10K 2.0 array. The conclusion is that both methods performed technically well, with high call rates and comparable and low rates of Mendelian inconsistencies. However, genotyping is less automated in GeneMapper® version 4.0 than in the Affymetrix software and thus more time consuming. (Journal of Biomolecular Screening 2009:92-96)

Genetic screening of Scandinavian families with febrile seizures and epilepsy or GEFS

Backgroundu2002–u2002 Mutations in the three genes SCN1A, SCN1B and GABRG2, all encoding subunits of ion channels, have been known to cause generalized epilepsy with febrile seizures plus (GEFS+) in families of different origin.