Combined Factor V and Factor VIII Deficiency

Pattern of Inheritance

F5F8D is an autosomal recessive bleeding disorder, which means that the disorder affects both males and females, and that both parents must carry the defective gene for their child to acquire F5F8D.

LMAN1 is encoded by a 29 kb gene that is located on chromosome 18q21 and contains 13 exons;¹⁷ MCFD2 is encoded by a 19 kb gene that is  located on chromosome 2p21 and contains four exons.⁴ There are more than 50 known mutations in the LMAN1 and MCFD2 genes can be found in the databases listed below). Most of the mutations identified on the LMAN1 gene are either nonsense or frameshift mutations, giving rise to truncated protein products that may be predicted to lack the normal LMAN1 function. In contrast, both null mutations and missense mutations have been identified in MCFD2.

Available databases of specific mutations include the following:

• Mutations Causing Rare Bleeding Disorders database, hosted on the website of the International Society on Thrombosis and Haemostasis (ISTH) (http://www.isth.org/resource/resmgr/publications/fv_and_viii_mutations-2011.pdf, accessed September 2018)
• The Human Gene Mutation Database (http://www.hgmd.cf.ac.uk/ac/index.php, accessed September 2018)

 

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