Molecular analysis of hereditary deficiency of the third component of complement (C3) in two sisters.
We report two sisters with hereditary deficiency of the third complement component (C3) and a homozygous mutation at C3303G (Tyr1081Stop) of the gene. They developed systemic lupus erythematosus-like symptoms during adolescence. Their C3 were not detected in serum immunochemically. Their mother and a brother had half of the normal C3 levels and a heterozygous mutation in the same position. Western blot analysis of murine L-cells transfected with the mutant C3 cDNA showed no C3 protein, however mRNA was detectable using reverse-transcriptase polymerase chain reaction. To the best of our knowledge, this is the first report of C3 deficiency due to a stop codon in the gene.
Matsuyama
W
W
Third Department of Internal Medicine, Kagoshima University Faculty of Medicine.
Nakagawa
M
M
Takashima
H
H
Muranaga
F
F
Sano
Y
Y
Osame
M
M
D000293:Adolescent; D000328:Adult; D015153:Blotting, Western; D018388:Codon, Terminator / Q000235:genetics*; D003176:Complement C3 / Q000172:deficiency* / Q000235:genetics*; D003545:Cysteine / Q000378:metabolism; D005260:Female; D005998:Glycine / Q000378:metabolism; D006720:Homozygote; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014443:Tyrosine / Q000378:metabolism
D018388:Codon, Terminator; D003176:Complement C3; D012333:RNA, Messenger; D014443:Tyrosine; D003545:Cysteine; D005998:Glycine