A Novel Mutation in the Complement Component 3 Gene in a Patient with Selective IgA Deficiency
Küçük Resim Yok
Tarih
2013
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
SPRINGER/PLENUM PUBLISHERS
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Purpose Immunological and molecular evaluation of a patient presenting with recurrent infections caused by Streptococcus pneumoniae and low complement component 3 (C3) levels. Methods Immunological evaluation included complement components and immunoglobulin level quantification as well as number and function of T cells, B cells and neutrophils. Serotype-specific immunoglobulin G antibodies against S. pneumoniae capsular polysaccharides were quantified by ELISA in serum samples before and after vaccination with unconjugated polysaccharide vaccine. For the molecular analysis, genomic DNA from the patient and parents were isolated and all exons as well as exon-intron boundaries of the C3 gene were sequenced by Sanger sequencing. Results A 16-year-old male, born to consanguineous parents, presented with recurrent episodes of pneumonia caused by S. pneumoniae and bronchiectasis. The patient showed severely reduced C3 and immunoglobulin A levels, while the parents showed moderately reduced levels of C3. Mutational analysis revealed a novel, homozygous missense mutation in the C3 gene (c. C4554G, p. Cys1518Trp), substituting a highly conserved amino acid in the C345C domain of C3 and interrupting one of its disulfide bonds. Both parents were found to be carriers of the affected allele. Vaccination against S. pneumoniae resulted in considerable clinical improvement. Conclusions We report a novel homozygous mutation in the C3 gene in a patient with concomitant selective IgA deficiency who presented with a marked clinical improvement after vaccination against S. pneumoniae. This observation underlines the notion that vaccination against this microorganism is an important strategy for treatment of PID patients, particularly those presenting with increased susceptibility to infections caused by this agent.
Açıklama
Anahtar Kelimeler
Complement deficiency, complement component 3, Streptococcus pneumoniae, primary immunodeficiency
Kaynak
JOURNAL OF CLINICAL IMMUNOLOGY
WoS Q Değeri
Q3
Scopus Q Değeri
Q1
Cilt
33
Sayı
1
