Characterization of non-expressed C4 genes in a case of complete C4 deficiency: identification of a novel point mutation leading to a premature stop codon
Författare
Summary, in English
The genetic basis of complete C4 deficiency in a patient with SLE was investigated. Previous studies have demonstrated that this patient has two different major histocompatibility complex (MHC) haplotypes that each contain a major deletion and a non-expressed C4 gene. In the present study, non-expression of the C4 genes was explained by the finding of two distinct C4 gene mutations. A previously described two base pair insertion in exon 29 of the C4 gene was detected in the paternal MHC haplotype [HLA-A2, B40, SC00, DR6]. The maternal haplotype [HLA-A30, B18, F1C00, DR3] carried a C4 gene with a one base pair deletion in exon 20 generating a premature stop codon. This mutation was neither found in 10 individuals with known non-expressed C4 genes nor in 9 individuals homozygous for the complotype F1C30. The isotype and allotype specific regions of the patient's C4 genes were sequenced, and both contained C4A3a sequence. In conclusion, two different MHC haplotypes resembling the extended haplotypes [HLA-A2, B40, SC02, DR6] and [HLA-A30, B18, F1C30, DR3] both contained a non-expressed C4A gene that was due to either of two distinct mutations, demonstrating the heterogeneous genetic background of C4 deficiency.
Avdelning/ar
Publiceringsår
1998
Språk
Engelska
Sidor
713-719
Publikation/Tidskrift/Serie
Human Immunology
Volym
59
Issue
11
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Immunology in the medical area
Status
Published
Forskningsgrupp
- Cardiovascular Research - Immunity and Atherosclerosis
ISBN/ISSN/Övrigt
- ISSN: 0198-8859