Skip to Main content Skip to Navigation
Theses

Recherche de nouvelles mutations génétiques à effet majeur dans la maladie de Crohn

Abstract : The NOD2 gene, involved in innate immune responses, has been found to be highlyassociated with Crohn’s Disease (CD). EPIMAD multiplex families with three or more CDaffectedmembers were previously reported to be related to a high frequency of NOD2gene mutations : R702W, G908R, and L1007fs. However, some rare EPIMAD CD multiplexfamilies were described without any of the common NOD2 linked-to-disease mutations.In order to identify new genetic variation(s) with amajor effect in CD, whole exomesequencing was performed on available subjects in a multiplex family (F49M), withoutknown common NOD2 mutations and comprising four patients affected with Crohn’s diseaseand three unaffected related subjects on two generations . A rare and, not yet, reportedmissense mutation of the NOD2 gene, N1010K, was detected and co-segregated acrossaffected patients (present in allmembers affectedwith CD and absent in all unaffected familialcontrol subjects). In silico evaluation of the deleterious effect of the mutation and3D modelling highlighted evidences for an adverse effect of the N1010K mutation withregard to the function of the NOD2 protein and the genetic risk of CD.Moreover, N1010Kand L1007fs as a compound heterozygous state in two, more severe CD family membersstrongly suggests that N1010K could be a new risk factor involved in Crohn’s disease geneticsusceptibility.In addition to the characterization of a new rare mutation of the NOD2 gene, 2 otherpotential variants have been identified : the D359H and G33V mutations, respectively, inthe BPIFB2 and DEFB132 genes. The proteins encoded by these genes are involved in thesame pathways : the pathway of defensins and the pathway of the innate immune system.In silico evaluation of the deleterious effect of mutations revealed a potential deleteriouseffect of D359H and G33V mutations. Thus, we could hypothesize that although the two mutations D359H and G33V are located on two different genes but involved in the same signaling pathways, they could act together and determine a cumulative dysfunctional effect also involved as determinants of the familial aggregation of Crohn’s disease in family F49M.Thus, for the F49M family, familial aggregation could be based on the accumulation of several deleterious mutations (N1010K, D359H and G33V).
Document type :
Theses
Complete list of metadatas

Cited literature [147 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02465045
Contributor : Abes Star :  Contact
Submitted on : Monday, February 3, 2020 - 4:16:12 PM
Last modification on : Wednesday, October 14, 2020 - 4:12:01 AM
Long-term archiving on: : Monday, May 4, 2020 - 4:31:40 PM

File

2019LILUS016.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02465045, version 1

Collections

Citation

Sara Frade Proud'Hon-Clerc. Recherche de nouvelles mutations génétiques à effet majeur dans la maladie de Crohn. Médecine humaine et pathologie. Université du Droit et de la Santé - Lille II, 2019. Français. ⟨NNT : 2019LIL2S016⟩. ⟨tel-02465045⟩

Share

Metrics

Record views

79

Files downloads

204