An evaluation of association between common variants in C4BPB/C4BPA genes and schizophrenia
NEUROSCIENCE LETTERS
Authors: Wang, Shuihong; Lu, Houquan; Ni, Jianliang; Zhang, Jiangtao; Tang, Wenxin; Lu, Weihong; Cai, Jun; Zhang, Chen
Abstract
Epidemiological studies have indicated that both maternal bacterial and viral infections during pregnancy increase the risk of schizophrenia among offspring, but to date there is not clear explanation for this increased risk. Previously, the decreased C4b-binding protein (C4BP), a potent circulating soluble inhibitor of the classical and lectin pathways of complement, was reported to be associated with risk of schizophrenia. Here, we analyzed 4 common single nucleotide polymorphisms (SNPs) of C4BPB and 5 SNPs of C4BPA in a group of 556 schizophrenia patients and a matched group of 610 healthy controls to see if the genes C4BPB and C4BPA, which encode C4BP, may confer a susceptibility to schizophrenia. Comparing the genotype and allele frequencies of those SNPs between cases and controls, we found no association between the C4BPB/C4BPA variants and schizophrenia. Our results provided preliminary evidence that C4BPB/C4BPA may not confer susceptibility to schizophrenia among Han Chinese. Further genetic studies from large-scale population are required to obtain more conclusive results. (c) 2015 Elsevier Ireland Ltd. All rights reserved.
Lack of sequence variations in the C4b-BP beta-chain in patients with type III protein S deficiency bearing the Ser 460 to Pro mutation: description of two new intragenic isomorphisms in the C4b-BP beta-chain gene (C4BPB)
BRITISH JOURNAL OF HAEMATOLOGY
Authors: Morbaeuf, O; Aiach, M; Gandrille, S
Abstract
Type III protein S (PS) deficiency, characterized by low levels of free PS and normal total PS levels, is often associated with the Ser 460 to Pro substitution. However, some patients bearing this mutation have normal PS levels, suggesting that another gene defect may account for this phenotype. We postulated that this defect was located in the C4b-BP beta-chain gene (C4BPB) and searched for a mutation in the coding regions of this gene in 35 propositi with type III PS deficiency and bearing the Ser 460 to Pro mutation. No mutations explaining the phenotype of type III PS deficiency were identified. We did, however, find two frequent nucleotide changes, one being located in the donor splice site of intron d and the second in the codon corresponding to Asn 137. We used these two polymorphisms to establish C4BPB gene haplotype in five informative type III PS-deficient families and exclude a role of the C4BPB gene in this phenotype of three of them. Finally, increased C4b-BP beta-chain levels were not responsible for the phenotype of type III PS deficiency as the C4BPB haplotype did not correlate with C4b-BP beta-chain levels.