A familial factor XIII subunit B deficiency.
A 32-year-old woman with a bleeding tendency born of a consanguineous marriage, was found to have factor XIII subunit B deficiency. An abnormally low level of factor XIII activity was initially noticed and this finding led to further studies of the proband and her family. The notable features were: undetectable subunit B of factor XIII in the proband and her brother and reduced levels of subunit B, 34-52%, in her parents and children. The proband's brother had a markedly decreased level of subunit A protein. The level of factor XIII subunit A in platelets of the proband was normal. The half-life of subunit A determined from the disappearance curve of infused factor XIII subunit A concentrate was approximately 3 d and this is the shortest estimate of the half-life of factor XIII to date. From these results, it is suggested that subunit A is unstable in plasma deficient in subunit B and subunit B stabilizes the A protein. This is the first report of congenital deficiency of factor XIII subunit B and this disorder is thought to be inherited as an autosomal recessive trait.
Saito
M
M
Department of Internal Medicine (III), Kanazawa University School of Medicine, Japan.
Asakura
H
H
Yoshida
T
T
Ito
K
K
Okafuji
K
K
Yoshida
T
T
Matsuda
T
T
D000328:Adult; D001779:Blood Coagulation Factors / Q000032:analysis; D001780:Blood Coagulation Tests; D005176:Factor XIII / Q000032:analysis; D005177:Factor XIII Deficiency / Q000151:congenital / Q000235:genetics*; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D010375:Pedigree
D001779:Blood Coagulation Factors; C064015:factor XIII subunit A; D005176:Factor XIII; C054380:factor XIIIb