Case: Female, 19 y.o., ethnicity unknown.

DiseaseAssertion: VWD2N

FamilyInfo: Proband has one older symptomatic sister who shares an identical compound heterozygous genotype, presenting with a mild bleeding tendency, reduced FVIII activity (20-30%), and severely reduced FVIII binding (<2%). The family features one younger unaffected sister who tested negative for both variants, and an unaffected carrier mother. Both parents had normal factor VIII, and there was no male relative with reduced factor VIII or bleeding symptoms.

ParentalGenotype(s): Mother is heterozygous for the c.2561G>A (p.R854Q) variant, negative for the c.2402G>A (p.S801N) variant, and has normal baseline factor VIII levels, confirming the sisters' variants are in trans. Father unavailable/not tested.

CasePresentingHPOs: HP:0004846 (Prolonged bleeding after surgery), HP:0003645 (Prolonged partial thromboplastin time).

CaseHPOFreeText: Index patient experienced bleeding complications following wisdom tooth surgery. Factor VIII binding activity is reduced at 32%. Reduced coagulation factor VIII activity (30%). Prolonged activated partial thromboplastin time (aPTT) of 37 seconds.

CaseNOTHPOs: HP:0001873 (Thrombocytopenia), HP:0012147 (Reduced quantity of von Willebrand factor), HP:0030130 (Impaired von Willebrand factor collagen binding activity).

CaseNOTHPOFreeText: Normal vWF antigen (vWF:Ag) levels (101%), normal vWF activity (116%), normal vWF-collagen-binding activity (104%), normal vWF multimer distribution structures, normal hemoglobin level (128 g/L), and normal Prothrombin Time (PT/QUICK) of 83%.

CasePreviousTesting: Siblings did not carry any known mutations in the F8 gene or the LMAN1 and MCFD2 genes (which encode for endoplasmic reticulum carrier proteins of coagulation factors V and VIII).

GenotypingMethod: Direct sequence analysis of VWF exons 18-20.

PreviouslyPublished: NA.

Gene: VWF

HGNCID: HGNC:12726

Variant: Heterozygous c.2561G>A (p.R854Q) and heterozygous c.2402G>A (p.S801N).

HGVS: (1) NM_000552.5:c.2561G>A (p.Arg854Gln) (2) NM_000552.5:c.2402G>A (p.Ser801Asn)

ClinVarID: (1) 296 (2) NA

CAID: (1) NA (2) CA383522023

gnomAD: (1) MAF of 0.005974 in the European (non-Finnish) population https://gnomad.broadinstitute.org/variant/12-6034812-C-T?dataset=gnomad_r4

(2) MAF of 0.00001098 in the South Asian population https://gnomad.broadinstitute.org/variant/12-6044331-C-T?dataset=gnomad_r4

Case: IP-6

DiseaseAssertion: VWD2

FamilyInfo: Mother is unaffected carrier of F8 Asn2129Ser. The VWF deletion of exons 33-34 segregates in 5 other affected male family members including the father and a full brother of IP-6. The patient’s father displayed a significant decrease in VWF:Ag and VWF:RCo, 13% and 7%, respectively, FVIII: C of 18.5% and the VWF:RCo/VWF:Ag ratio of 0.5 pointing out to type 2 VWD.

ParentalGenotype(s): Mother is heterozygous for F8FAsn2129Ser. Father is heterozygous for VWF deletion of exons 33-34.

CasePresentingHPOs:

CaseHPOFreeRext: VWF:Ag (17%), VWF:RCo (9%) and FVIII:C (1,9%). Bleedings in the oral cavity, ankle joint and hematomas.

CaseNOTHPOs:

CaseNOTHPOFreeText:

CasePreviousTesting: Direct sequencing of exons 2–52 including exon/intron boundaries of the VWF gene

GenotypingMethod: multiple ligation‐dependent probe amplification (MLPA; using kit P011 and P012; MRC Holland, Amsterdam, the Netherlands) according to the manufacturer’s instructions. The PCR products were run on an ABI PRISM 3130XL sequencer with the GeneScan 500 LIZ size standard and analyzed using GeneMapper Software 5.0 (Applied Biosystems, Darmstadt, Germany). Dosage analysis based on a comparison between deleted and reference wild‐type DNA samples was performed using the Excel‐based software Coffalyser V9.4 (MRC Holland).

PreviouslyPublished: NA

Gene:VWF

Variant: deletion of exons 33-34

HGVS:

ClinVarID:

CAID:

gnomAD:

MultipleGeneVariants:

GeneName: F8

Variant: Asn2129Ser

ClinVarID or CAID:

gnomAD:

Case#: 3G

DiseaseAssertion:

FamilyInfo: Her father (3F), who reported mild bruising symptoms, and both asymptomatic younger male siblings (3H and 3J) were also investigated. All family members were found to be heterozygous for a previously described mutation in exon 30:c.5191 T → A, resulting in Ser1731Thr.

CaseHPOFreeText4: In family 3, the female proposita (3G) presented in childhood with epistaxis and easy bruising. VWF:Ag and VWF:RCo were borderline low in 3F and 3G but normal in the asymptomatic brothers, 3H and 3J. Multimer analysis was normal in all family members tested (Figure 1). VWF:CB binding to type I collagen was reduced in all family members (CB/Ag ratio 0.4-0.7), whereas only one (3G) showed a reduction in CB:Ag ratio with type III collagen.

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: heterozygous for a previously described mutation in exon 30:c.5191 T → A, resulting in Ser1731Thr

HGVS: NM_000552.5(VWF):c.5191T>A (p.Ser1731Thr)

ClinVar: 100420

CAID: CA228704

gnomAD: 0.004289 in middle eastern pop

Case#: 2D

DiseaseAssertion:

FamilyInfo: Her son 2E had mild bruising and epistaxis.

CaseHPOFreeText: The proposita (2D) in family 2 was investigated after a postpartum hemorrhage requiring blood transfusion. She gave a longstanding history of menorrhagia, and her calculated bleeding score was 10, the highest of all the persons in this study. VWF:Ag, VWF:RCo, and multimer analysis were all normal. VWF:CB was significantly reduced with both types I and III collagen, resulting in CB:Ag ratios of 0.2 to 0.4. Closure times in the PFA-100 were normal in 2D with both cassettes (Coll/Epi, 111 seconds; Coll/ADP, 98 seconds). The discrepant reduction in VWF:CB persisted after DDAVP administration to 2D despite normalization of both VWF:Ag and VWF:CB (samples taken 90 minutes after DDAVP administration showed VWF:Ag 191 IU/dL, VWF:CB 67 IU/dL, CB:Ag ratio = 0.35).

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: Her and son were shown to be heterozygous for a novel mutation in exon 31:c.5347 T → G resulting in Ser1783Ala

HGVS: NM_000552.5(VWF):c.5347T>G (p.Ser1783Ala)

ClinVar: 31012

CAID: CA228715

gnomAD: 0.0006918 in south asian pop

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

Case#: MK0251

DiseaseAssertion: Type 2 VWD

CaseHPOFreeText: 51 year old, female, VWF:AG LEVELS = 60

Gene: VWF

Variant: compound heterozygous for 4751A>G (p.Y1584C) and c.7483del (p.Leu2495CysfsTer8) variants

ClinVar: 310 (p.Y1584C) and 631687 (p.Leu2495CysfsTer8)

gnomAD: absent grpmax (p.Leu2495CysfsTer8), grpmax of 0.004019 based on european non finnish pop (p.Y1584C)