To summarise:
38 year old man with incidental finding of a prolonged APTT on pre-op bloods.

History: major orthopaedic surgery without bleeding. Some bleeding post dental extraction but no intervention needed. No family history.

Investigations: no LA. Factor assays show an isolated FVIII deficiency at 19%.

Your comments
Most people were surprised that the patient didn’t bleed during orthopaedic surgery. The dental history lead to requests to look for evidence of Von Willebrands Disease. This is an important differential in patients with mucosal bleeding. Type 2N VWD results in poor FVIII transport and low levels on assay so is definitely in the differential here.

However it is a red herring in this case!
The patient is seen in the Haemophilia OPC and bloods sent for FVIII and VWD gene analysis. The VWD results were normal, but a FVIII gene mutation was found.

Questions

Can you think of a mutation/phenomenon that can explain this patient’a unusual history? How would you test for this?

How should he be managed in his upcoming surgery?

Any BMSs fancy explaining the tests involved here? Reply on the blog and we’ll publish your explanation in the case summary.

please reply on twitter using the teamhaem hashtag. Thanks for following this case.