1/3. Two novel and one recurrent missense mutation in the factor XIII A gene in two Dutch patients with factor xiii deficiency.Congenital factor XIII (FXIII) deficiency is a rare autosomal recessive disorder, usually attributed to a defect in the FXIII A subunit, whose genetic basis has been studied in a number of cases. We describe here the genetic variations found in two unrelated patients with FXIII deficiency. Both patients, under prophylactic substitution with FXIII concentrate, showed low plasma FXIII A subunit antigen levels with undetectable A subunit antigen in the platelets and normal plasma B antigen levels, which indicate that the defects are present in the A subunit of the molecule. Both probands were heterozygous for a previously reported G-->A transversion in exon 8 of the FXIII A subunit gene (Arg326Gln substitution). Proband 1 was also heterozygous for a novel G-->T transversion in exon 7, which predicts a Val316Phe substitution. Two of her sons were heterozygous for this mutation and showed low FXIII activity and FXIII A subunit antigen levels. Val316 is a well-conserved amino acid among the transglutaminase family, located within the core domain, close to the Cys314 member of the catalytic triad. Proband 2 had a unique 2-bp (TT) insertion in one of the alleles within or adjacent to the -7 to -20 T tail of intron A. This insertion was not found in 50 healthy individuals, which supports this being the second mutation in this patient.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/3. Glanzmann's thrombasthenia associated with a transient deficiency of factor XIII.A three-year-old girl suffering from ecchymoses developed severe epistaxis. The diagnosis of thrombasthenia was made on the basis of platelet aggregation studies, flow cytometric analysis with monoclonal antibodies and gel electrophoretic analysis. In addition, coagulation studies at the time of epistaxis repeatedly showed a transient deficiency of factor XIII activity and antigen.- - - - - - - - - - ranking = 0.25keywords = antigen (Clic here for more details about this article) |
3/3. A new family with congenital factor xiii deficiency showing a deficit of both subunit A and B. Type I factor xiii deficiency.In this study we present a new case of factor xiii deficiency. The proposita, a 34 year old woman, showed a deficiency of both subunit a and subunit b, and a moderate bleeding tendency. Because of the concomitant decrease of subunits a and b the proposita is considered to be an example of Type I disease. Factor XIII levels were less than 10% both as activity and antigen. Several family members showed intermediate levels of both subunit a and b and were asymptomatic. They were considered to be heterozygotes. The hereditary pattern is autosomal incompletely recessive. Type I disease appears much less frequent than Type II.- - - - - - - - - - ranking = 0.25keywords = antigen (Clic here for more details about this article) |