A novel RNA splice site mutation in the C1 inhibitor gene of a patient with type I hereditary angioedema.
We describe a patient with type I hereditary angioedema presenting recurrent episodes of skin swelling and abdominal pain. Laboratory examination showed reduced levels of CH50 and C4 with a normal C3 level. The C1 inhibitor was decreased to 7.0 mg/dl (normal, 10-25 mg/dl) with a remarkably reduced activity (<25%; normal, 80-125%). DNA analysis of the C1 inhibitor gene revealed a novel point mutation at the 3' acceptor mRNA splice site of the intron 5 (G-->A at nucleotide 8722). This mutation may abolish the correct splicing of the intron 5 and create unstable mRNA.
Sekijima
Yoshiki
Y
Third Department of Medicine, Shinshu University School of Medicine, Matsumoto.
Hashimoto
Takao
T
Kawachi
Yasuhiro
Y
Koshihara
Hiroshi
H
Otsuka
Fujio
F
Ikeda
Shu-ichi
S
D000799:Angioedema / Q000235:genetics*; D003174:Complement C1 Inactivator Proteins / Q000235:genetics*; D050718:Complement C1 Inhibitor Protein; D015853:Cysteine Proteinase Inhibitors / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017354:Point Mutation / Q000502:physiology*; D022821:RNA Splice Sites / Q000235:genetics*; D017422:Sequence Analysis, DNA
D003174:Complement C1 Inactivator Proteins; D050718:Complement C1 Inhibitor Protein; D015853:Cysteine Proteinase Inhibitors; D022821:RNA Splice Sites