A novel Cys328-terminator mutant implicated in severe coagulation factor XIII deficiency: a case report.

Background: Factor XIII (FXIII) deficiency is an extremely rare bleeding disorder that is commonly due to mutations in the FXIIIA subunit gene (F13A1), and it has been reported to have a prevalence of one per 2 million. We describe a new genetic variant in the F13A1 gene that caused a patient to suffer from lifelong hemorrhagic diathesis.

Case presentation: We evaluated a 20-year-old female with umbilical cord bleeding after birth, an intracerebral hemorrhage at age 6, and other bleeding episodes, including hematuria and cephalohematoma, who suffered from a lifelong hemorrhagic diathesis. The clot solubility test showed that the clot of the patient was dissolved in urea solution at 10 h. Genetic testing identified a novel homozygous mutation, c.984C > A(p. Cys328stop), resulting in a premature stop codon in exon 8 of the F13A1 gene. The results obtained with ClusterX software showed that Cys328 of exon 8 in the F13A1 gene is highly conserved among species.

Conclusion: We reported a novel homozygous mutation in the F13A1 gene in a factor XIII (FXIII)-deficient patient, which adds a new point mutation to the mutant library. In this paper, we discuss other aspects of the disease, including laboratory examination, homogeneous sequence alignment and molecular modeling.