Activity and levels of factor XIII in a Venezuelan admixed population: association with rs5985 (Val35Leu) and STR F13A01 polymorphisms.
BACKGROUND
The single nucleotide polymorphism Val35Leu has been described within the A subunit of gene Factor XIII (FXIII-A) in association with an increase of FXIII activity. In the gene's promoter region STR F13A01 is present, however there is no available data related about its influence on the expression of FXIII.


METHODS
Blood samples were obtained from apparently healthy and unrelated biologically individuals from northeastern area of Venezuela. The system Val35Leu was amplified by PCR-RFLP using MseI as restriction enzyme. FXIIIA and FXIIIB levels were measured by rocket- immunoelectrophoresis. FXIII activity was measured with a Berichrom kit and fibrinogen by clot weigh method.


RESULTS
FXIII-A had an activity range between 50-184% and FXIII-B between 50-155%. FXIII activity had a range of 59-147%. Fibrinogen was found between 122-502 mg/dL. None of these values showed association with Val35Leu genotypes. In the third fibrinogen tertile a higher FXIII activity was found (96 ± 24%) and a higher frequency of Leu/Leu genotype (7.02%). A significant correlation between fibrinogen and FXIII activity (r = 0.2706, p > 0.01) was observed. Nine different alleles were detected in the STR polymorphism, with the most frequent alleles being 7 (24.70%), 6 (15.06%), 5 (22.29%), 4 (18.07%), and 3.2 (13.25). The results suggest an increase in FXIII activity as the number of repetitions in F13A01 increased up to allele 5.


CONCLUSIONS
This study offers new genetic information of FXIII activity and levels reference values from Venezuelan human population.
Laboratorio de Genética Humana, Centro de Medicina Experimental, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
Merlyn
M
Vívenes
Dinorah
D
Castro de Guerra
Alvaro
A
Rodríguez-Larralde
Carmen Luisa
CL
Arocha-Piñango
Belsy
B
Guerrero
D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D005176:Factor XIII / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D005340:Fibrinogen / Q000235:genetics / Q000378:metabolism; D005787:Gene Frequency; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D012016:Reference Values; D014687:Venezuela; D055815:Young Adult
D005340:Fibrinogen; D005176:Factor XIII