Background: Investigation of rare bleeding disorders in Latin-America.
Objectives: The report of a new case of FX deficiency due to a compound heterozygosis.
Methods: Accepted clotting procedures were used. Sequencing of DNA was carried out by means of Applied Biosystems Instruments.
Results: A compound heterozygote due to the association of a new mutation (Gla72Asp) with an already known mutation (Gly154Arg) of the FX gene is reported. The proposita is a 38 year old female who had a moderate bleeding tendency (menorrhagia, epistaxis, easy bruising). The proposita has never received substitution therapy but in the occasion of a uterine biopsy. The mother was asymptomatic but was a heterozygote for the new mutation. The father was asymptomatic but had deserted the family and could not be investigated. After this abandonment the mother of the proposita re-married with an asymptomatic man and she gave birth to a son who was asymptomatic but was also heterozygous for the new mutation (Gla72Asp). As a consequence it has to be assumed that the first husband of the mother of the proposita was heterozygous for the known mutation (Gly154Arg).
Conclusions: This is the third case of a new mutation in the FX gene reported, during the past few years, in Argentina.
Keywords: Factor X, deficiency, compound heterozygosis, bleeding, menorrhagia.