Coagulation Factor XIIIA Subunit Missense Mutations Affect Structure and Function at the Various Steps of Factor XIII...

Area of Science:

• Hematology
• Molecular Genetics
• Biochemistry

Background:

• Inherited Factor XIII (FXIII) deficiency presents as severe or mild forms, influenced by genotype and phenotype.
• Mild FXIII deficiency, often heterozygous, is typically asymptomatic unless trauma occurs.
• Many mild FXIII deficiency mutations lack comprehensive characterization via expression studies.

Purpose of the Study:

• To characterize the expression phenotype of 16 previously reported missense mutations in the F13A1 gene associated with mild FXIII deficiency.
• To functionally categorize these mutations based on their impact on FXIII protein expression and function.
• To correlate in vitro findings with in silico analyses for a deeper understanding of mutation effects.

Main Methods:

• Transient expression of 16 F13A1 missense mutations.
• Analysis of expression phenotype using various determination assays.
• In silico analysis to complement in vitro expression data.

Main Results:

• Identified distinct expression phenotypes for the analyzed mutations, indicating varied impacts on FXIII function.
• Demonstrated that mutations can influence different functional aspects of the FXIII protein.
• Highlighted specific mutations (p.Arg716Gly, p.Arg704Gln, p.Gln602Lys, p.Leu530Pro, p.His343Tyr, p.Pro290Arg, p.Arg172Gln) with substantial effects even in heterozygous states.

Conclusions:

• The expression phenotype provides a functional categorization for F13A1 mutations causing mild FXIII deficiency.
• Several heterozygous mutations significantly impair FXIII protein function, necessitating further clinical correlation.
• Comprehensive characterization of mild FXIII deficiency mutations is crucial for understanding their clinical relevance.