Pseudohemophilia of Erik von Willebrand caused by homozygous one nucleotide deletion in exon 18 of the VW-factor gene

Table 6 The 2006 Antwerp Classification of recessive von Willebrand disease type 3, recessive severe on Willebrand disease type 1 and obligatory carriers of a null or missense allele with asymptomatic or mild on Willebrand disease type 1 and variable penetrance of bleeding tendency

Category VWD	BT	FVIII: C (%)	VWF (%) Ag	RCo	RIPA	Bleeding type	VWF gene mutation
Severe type 3	↑↑↑	1-9	zero	zero	zero	Severe	Double
Recessive						Hemophilia	Nonsense
Severe type 1	↑↑↑	9-40	1-10	0-6	zero	Moderate	Double
Recessive VWD						Severe	Missense
Blood group O (30-32)	N	35-150	35-150	35-150	N	Asymp	None
(Pseude-VWD)						Very mild
Carrier type 3	N↑	30-140	15-90	15-90	N	Asymp	Single
Minor influence (-10%)						Very mild	Non-sense
of bloodgroup O							(null allele)
Carrier type 1	N	N	N	N	N	Asymp	Single
(polymorphism)							Missense
Mild type 1	N↑	20-80	20-50	20-50	N	Mild	Mis/Non-sense
Recessive or							or Y1584C/
variable penetrance and multigenetic backgroud							Bloodgroup O[19
Dominant type 1	N↑	20-80	10-40	0-30	N	Mild	Single
Secretion defect	↑/↑↑	5-20	5-20	5-20		Moderate	Missense
Dominant type 1
Vicenza	N/↑	< 15	< 15	< 15		Moderate	SingleR120SH
							Missense

VWF: von Willebrand factor; VWD: von Willebrand disease; RIPA: Ristocetin induced platelet aggregation.