Identification of two point mutations associated with inherited antithrombin deficiency

Area of Science:

• Biochemistry
• Genetics
• Molecular Biology

Background:

• Antithrombin (AT) is a key anticoagulant protein inhibiting serine proteases.
• Inherited AT deficiency increases the risk of venous thrombosis.
• Understanding pathogenic mechanisms of AT mutants is crucial for managing thrombotic risk.

Purpose of the Study:

• Investigate the pathogenic mechanisms of two natural antithrombin (AT) mutants, W221C and M284R, in inherited AT deficiency.
• Elucidate how these mutations affect AT production, secretion, and structure.
• Enhance understanding of the genetic basis of AT deficiency.

Main Methods:

• Analyzed 9 unrelated patients with inherited AT deficiency.
• Sequenced the SERPINC1 gene to identify mutations.
• Utilized enzyme-linked immunosorbent assay and heparin affinity chromatography to assess AT function.
• Employed computational simulations to model mutant AT behavior.

Main Results:

• Identified two point mutations, W221C and M284R, in patients with inherited AT deficiency.
• W221C mutation potentially impairs AT secretion.
• M284R mutation significantly decreased total AT production (p=0.029) and both mutants delayed AT release.
• Seven of nine patients experienced venous thrombotic events.

Conclusions:

• W221C and M284R mutations in the SERPINC1 gene alter AT production and structure.
• These findings improve comprehension of the genetic underpinnings of AT deficiency.
• The study highlights potential clinical implications for inherited AT deficiency management.