Talks
Presentation Type
Oral Presentation
Discipline Track
Translational Science
Abstract Type
Research/Clinical
Abstract
Background: Hemophilia A (HA) is caused by deficiencies in plasma-FVIII and heterogeneous factor-VIII-gene mutations that impair intrinsic coagulation amplification. In severe hemophilia A patients (HAPs), FVIII infusions are begun at toddlerhood to prevent hemarthrosis induced crippling. However, approximately 30% of these patients develop FVIII inhibitors. Gain-of-function mutations in the common pathway of coagulation increases coagulation potential and decreases bleeding and FVIII-utilization in HAPs which should decrease FVIII-inhibitor-risk. We identified loss-of-function mutations in this pathway which decrease coagulation-potential as they increase FVIII-inhibitor risk in HAPs.
Methods: We screened Mexican-American-pedigrees of the South-Texas-Family-Study (STFS) for protein-altering-variants. Subjects were genotyped using Illumina-exome-24-chip. Protein-altering-variants were analyzed for associations with FII:C, PT, and aPTT. Linear-mixed-model-analyses was performed to estimate trait-heritability and examine single-nucleotide-variations (SNVs) for gene association. Significant associations’ p-values fell below Bonferroni-adjusted significance level.
Results: Heritability-estimates for FII:C, aPTT, and PT were highly-significant with p-values of 0.49, 0.49, and 0.54 (for all, pT in the FII-gene (F2)—which encodes 543R>L and has a large effect-size on each trait (for all, pT have lower FII:C levels but correspondingly prolonged aPTT and PT times.
Conclusion: We hypothesize that FII-543R>L (Prothrombin-RGV) likely contributes to the high-incidence of FVIII-inhibitor-development in HA-patients of Mexican-ancestry, resulting in higher risk of developing anti-tFVIII-antibodies than patients without the variant. Patients with the RGV variant are likely to bleed more which can require surgery, further increasing the development of FVIII inhibitor development.
Recommended Citation
Jhaveri, Shuchita; Nguyen, Hoang; Almeida, Marcio A.A.; Diego, Vincent P.; Kumar, Satish; Peralta, Juan M.; Curran, Joanne E.; Luu, Bernadette W.; Lehman, Donna M.; DeFronzo, Ralph A.; Almasy, Laura; Williams-Blangero, Sarah; Duggirala, Ravi; Blangero, John; and Howard, Tom E., "The Development of FVIII Inhibitor in Hispanic American Patients with Hemophilia A Critically Impacts Coagulation Potential" (2023). Research Symposium. 47.
https://scholarworks.utrgv.edu/somrs/theme1/track1/47
Included in
The Development of FVIII Inhibitor in Hispanic American Patients with Hemophilia A Critically Impacts Coagulation Potential
Background: Hemophilia A (HA) is caused by deficiencies in plasma-FVIII and heterogeneous factor-VIII-gene mutations that impair intrinsic coagulation amplification. In severe hemophilia A patients (HAPs), FVIII infusions are begun at toddlerhood to prevent hemarthrosis induced crippling. However, approximately 30% of these patients develop FVIII inhibitors. Gain-of-function mutations in the common pathway of coagulation increases coagulation potential and decreases bleeding and FVIII-utilization in HAPs which should decrease FVIII-inhibitor-risk. We identified loss-of-function mutations in this pathway which decrease coagulation-potential as they increase FVIII-inhibitor risk in HAPs.
Methods: We screened Mexican-American-pedigrees of the South-Texas-Family-Study (STFS) for protein-altering-variants. Subjects were genotyped using Illumina-exome-24-chip. Protein-altering-variants were analyzed for associations with FII:C, PT, and aPTT. Linear-mixed-model-analyses was performed to estimate trait-heritability and examine single-nucleotide-variations (SNVs) for gene association. Significant associations’ p-values fell below Bonferroni-adjusted significance level.
Results: Heritability-estimates for FII:C, aPTT, and PT were highly-significant with p-values of 0.49, 0.49, and 0.54 (for all, pT in the FII-gene (F2)—which encodes 543R>L and has a large effect-size on each trait (for all, pT have lower FII:C levels but correspondingly prolonged aPTT and PT times.
Conclusion: We hypothesize that FII-543R>L (Prothrombin-RGV) likely contributes to the high-incidence of FVIII-inhibitor-development in HA-patients of Mexican-ancestry, resulting in higher risk of developing anti-tFVIII-antibodies than patients without the variant. Patients with the RGV variant are likely to bleed more which can require surgery, further increasing the development of FVIII inhibitor development.