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.
Academic/Professional Position
Medical Student
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.