Case: 6 , F, 15, Italian

DiseaseAssertion: VWD type 3

FamilyInfo: Consanguinity: no

ParentalGenotype: n/a

CasePresentingHPOs: n/a

CaseHPOFreeText: VWF:Ag (U/dl): <1, Bleeding symptoms: Severe

CaseNotHPOs: n/a

CaseNotHPOFreeText: Anti-VWF alloantibodies: no

CasePreviousTesting: n/a

Gene: VWF

Variant:

2269delCT (FS), Exon 17

7729+7C→T (intronic), Exon 45

Compound Heterozygous

Note: Article assumes that 7729+7C→T would be a frameshift mutation. No potential splice site mutation was confirmed at the mRNA level; “Splice Site Prediction program” found all mutations likely to disrupt normal splicing. No possible splice site mutation could be identified on 100 chromosomes from a group of 50 normal subjects with same genetic background as patients, excluding the possibility that these mutations represent common polymorphisms.

Case-Individual:

Case: 50-year old male of consanguinous parents

DiseaseAssertion: severe Type 1 Von Willebrand Disease, previously misclassified as Type 3

Family Info: Proband's parents and offspring had the same mutation, but at the heterozygous level; all asymptomatic

Parental Genotype: N/A

CasePresentingHPOs: HP:0000421, HP:0030140, HP:0006298, HP:0005261

Epistaxis, oral cavity bleeding, severe hemorrhagic complications after tooth extractions (HP is called Prolonged bleeding after dental extraction), hemarthrosis (joint bleeding)

CaseHPOFreeRext: Lifelong history of severe bleeding, frequent hematomas, bleeding from minor wounds (possibly HP:0030138, excessive bleeding from superficial cuts), impaired hemostatic picture, extremely high ISTH bleeding score (proband's was 30 whereas males usually range from 0-3)

CaseNOTHPOs: N/A

CaseNOTHPOFreeText: N/A

CasePreviousTesting: N/A

GenotypingMethod: Sequencing reactions were performed in an ABI3130 XL Genetic Analyzer; digital droplet polymerase chain reaction (ddPCR) assays were performed (in multiplex); in vitro expression also performed, then electrophoresis system used to run Western blot

Gene: VWD

HGVS: NM_000552.5:c.2269_2270del

Variant: Gene null homozygous c.2269_2270del mutation

ClinVarID: 100207

CAID: CA228313

gnomAD: MAF of 0.000002542 (3 of 1180022 alleles) in the European non-Finnish population

Case: Patient 10, M, Hungarian

DiseaseAssertion: VWD type 3

FamilyInfo: compatible with recessive inheritance

ParentalGenotype(s): n/a

CasePresentingHPOs: n/a

CaseHPOFreeRext: Bleeding score: 18, VWF:Ag (IU dL−1): < 1, VWF:CB (IU dL−1): < 1, FVIII:C (IU dL−1): 3, VWF:RCo below detection limit (<10 IU dL−1), not detectable VWF on multimer gels

CaseNOTHPOs: n/a

CaseNOTHPOFreeText: no inhibitor detected, did not become refractory to factor replacement therapy

CasePreviousTesting: n/a

Gene: VWF

Variant:

c.2269_2270delCT (p.L757VfsX22), Exon 17

c.2435delC (p.P812RfsX31), Exon 18

Intron 40 VNTR: 17/18

Note: multimer electrophoresis, Recombinant VWF antigen concentrations and Collagen binding activity (VWF:CB) measured by ELISA, direct sequencing of the 51 exons and the exon‐intron boundaries, Breakpoint analysis and breakpoint‐specific PCR

Case: 4, M, 5, Italian

DiseaseAssertion: VWD type 3

FamilyInfo: Consanguinity: not reported

ParentalGenotype: n/a

CasePresentingHPOs: n/a

CaseHPOFreeText: VWF:Ag (IU/dL): <1, FVIII:C (IU/dL): 17, Bleeding Score: 6

CaseNotHPOs: n/a

CaseNotHPOFreeText: Anti-VWF alloantibodies: no

CasePreviousTesting: n/a

Gene: VWF

Variant:

c.2269delCT (p.Leu757ValfsX22), Exon 17, Homozygous

Note: paretns investigated for the probands defects and confirmed to carry the expected mutation at the heterozygous state

Case: Croatian adult patient

DiseaseAssertion: VWD1

FamilyInfo: Not specified

ParentalGenotype(s): Not specified

CasePresentingHPOs: HP:0001892, HP:0011890, HP:0000132, HP:0002239, HP:0000790, HP:0001342

CaseHPOFreeText: Reduced VWF:GPIbM of 41.3%. Normal VWF:Ag of 67.8%, FVIII:C of 72% and VWF:CBA of 50.5%. Normal multimer distribution.

CaseNOTHPOs: Not specified

CaseNOTHPOFreeText: Normal multimer size distribution (tested in Agarose gel).

CasePreviousTesting: Not reported

GenotypingMethod: Illumina NGS, custom designed panel covering all 52 exons as well as intronic flanking regions and promoter region of VWF gene.

PreviouslyPublished: PMID: 34351388

Gene: VWF

Variant: c.2269_2270delCT

HGVS: NM_000552.4:c.2269_2270delCT (p.Leu757ValfsTer22)

ClinVarID: 100207

CAID: CA228313

**gnomAD: ** 0.000008794 in European (non-Finnish), 0.0003115 in XX and 0.0001629 in XY

https://gnomad.broadinstitute.org/variant/12-6155899-CAG-C?dataset=gnomad_r2_1