Case#: 1A

DiseaseAssertion:

FamilyInfo: Family 1. Her 2 offspring, 1B (son) and 1C (daughter), reported minor bleeding symptoms that had not required treatment. 1B was found to be heterozygous for Trp1745Cys only and 1C was heterozygous for Arg760His only, confirming that these mutations are in trans in 1A.

CaseHPOFreeText4: was an elderly woman with lifelong bleeding episodes, including epistaxis, ecchymosis, menorrhagia, and prolonged bleeding after dental extractions, requiring multiple medical interventions. The coexistence of both mutations appears to produce a more significant bleeding disorder as the bleeding score in 1A (8) was higher than that in either of her children (4 and 2). The position of Trp1745 in the A3 domain is shown in Figure 2. Both persons with this mutation (1A and 1B) had markedly reduced ratios of VWF collagen-binding activity to VWF antigen (CB:Ag) with type III collagen (0.1 and 0.3, respectively) and type I collagen (0.2 and 0.3, respectively). The ratio of VWF:RCo to VWF:Ag (RCo:Ag) was near unity in both persons, and VWF multimer analysis (Figure 1B) and RIPA were normal. Closure times in the PFA-100 were mildly prolonged with the ADP cartridge (1A = 173 seconds, 1B = 189 seconds, NR < 112 seconds). With the epinephrine cartridge, the closure time was prolonged in 1A only (1A = 271 seconds, 1B = 90 seconds, NR < 179 seconds).

CasePreviousTesting: Fifty-one primer sets were used to amplify the essential regions of VWF (52 exons, flanking intronic regions, 5′ promoter region, and the 3′ untranslated region).

Gene: VWF

Variant: 1A demonstrated compound heterozygosity for 2 mutations in the VWF gene. The first is a novel mutation in exon 30:c.5235 G → T resulting in Trp1745Cys and the second is c.2279 G → A resulting in Arg760His.

HGVS: NM_000552.5(VWF):c.5235G>T (p.Trp1745Cys), NM_000552.5(VWF):c.2279G>A (p.Arg760His)

ClinVar: 100421, 31011

CAID: CA228706, CA228316

gnomAD: 8.474e-7 in the european non finnish pop, 0.00002669 in the African American population