Variation in immunoregulatory genes determines the clinical phenotype of common variable immunodeficiency

Abstract

Variation in clinical phenotype is a hallmark of many complex diseases. The cause of this clinical heterogeneity is unknown, but it may be determined by genetic factors distinct from those conferring disease susceptibility. Common variable immunodeficiency (CVID) is a complex disease of unknown aetiology and diverse clinical manifestations. We have developed a unified polymerase chain reaction and sequence-specific primer (PCR-SSP) method to simultaneously genotype multiple polymorphisms under identical conditions, and have used this method to test the hypothesis that the clinical phenotype of CVID is determined by immunoregulatory gene polymorphism. Twenty-three polymorphisms in 13 genes were studied in 163 CVID patients. Vitamin D receptor and IL-6 alleles were associated with immunophenotypic abnormalities characteristic of more severe disease; and tumour necrosis factor and IL-10 alleles conferred susceptibility to the granulomatous form of CVID in an interacting fashion. These findings demonstrate that different clinical features of a disease may have unique pathogenetic abnormalities, determined by multiple interacting genetic factors. The ease of application of this efficient, robust genotyping technique to polymorphisms throughout the genome will make it a powerful tool in the investigation of the genetic basis of phenotypic variability in a wide variety of diseases.

Low frequency of HLA DRB1*03 – DQB1*02 and DQB1*0302 haplotypes in Romania is consistent with the country's low incidence of Type I diabetes

“…PCR amplification and electrophoresis for HLA-DQB1 and INS-HphI alleles was performed as previously described [25,26,27]. Genomic DNA was amplified in 13 mg reactions.…”

“…For each PCR, the reaction mix consisted of base buffer (67 mmol TRIS base pH 8.8, 16.6 mmol ammonium sulphate; 0.01 % v/v Tween); 2 mmol magnesium chloride; 200 mmol of each of dATP, dGTP, dCTP and dTTP; 0.1875 units of Taq polymerase (Advanced Biotechnology, London, UK) and between 40±60 ng DNA. DNA was briefly mixed with the buffer [26] and 8 ml of DNA/buffer mix was aliquoted onto 5 ml primer mix. All the reactions were performed under 10 ml mineral oil (Sigma, Dorset, UK) in 96 well PCR plates (Advanced Biotechnology).…”

“…Our study aimed to evaluate the IDDM 1 (HLA-DQB1 alleles and an allele of DRB1, DRB1*03) and IDDM 2 (INS ±23 HphI Single Nucleotide Polymorphism (SNP)) status in a large group of Type I diabetic Romanian patients. Using a family study approach, we typed 204 Romanian Type I diabetic families by employing a single-protocol method of genotyping for multiple HLA and non-HLA polymorphisms under identical conditions, with the SSP-PCR technique [25,26,27]. To compare results, we used data from another group of families with Type I diabetes from Sardinia [28], a ªhot spotº in incidence on the European map [1,2].…”

Association of a new mannose-binding lectin variant with severe malaria in Gabonese children

“…16,18,20 To date, the MBL2*XA, B, C and D variants have been associated with the predisposition and/or severity of various immunodeficiencies, autoimmune and infectious diseases in childhood and adult age (for a review, see Eisen and Minchinton; Kilpatrick 21,22 ). Alternatively, the MBL2*HA diplotype and/or high plasma concentrations of MBL multimers have been associated with protection to some of these diseases, 14,23,24 but to predispose to and/ or to increase the severity of leprosy, tuberculosis, 21,25 visceral leishmaniasis, 26 sporadic ulcerative colitis 27 and rheumatic heart disease. 28 A total of 96% of the variation in the plasma levels of MBL multimers can be explained by genetic polymorphisms.…”

Variation in immune response genes and chronic Q fever. Concepts: preliminary test with post-Q fever fatigue syndrome

“…When two or more polymorphic sites are present within the one gene, forward and reverse allelic specific primers are used. 17 In total, 25 polymorphic variants were analysed spanning 14 genes. Genes examined for polymorphic variants included MBL, VDR, IL-1RA, IL-1b, IL1-R1, IL-4, IL-6, IL-10, TGFb, INFg, ICAM1, TNFa, E-selectin and L-selectin.…”