LMAN1, MCFD2 mutation screen for Combined FV & FIII deficiency

Combined deficiency of FV and FVIII is due to mutations in either LMAN1 or MCDF2, genes which code for proteins which form a complex required for the export of FV and FVIII from the endoplasmic reticulum. A defect in this transport mechanism leads to mild deficiencies of both FVIII and FV - levels are usually between 5-30%. This autosomal recessive disorder, with a frequency estimated at 1:100,000 to 1:1,000,000, generally presents as mucosal bleeding and menorrhagia in females, with exessive trauma related bleeding. This rare disorder, although found world-wide, is more common in the Mediterranean basin, the result of founder effect and consanguinity.
Thus far mutations have more commonly been identified in LMAN1, although this may be biased by the fact that it was identified before MCFD2.