Disease: Von-willebrand Disorder Type 3
Patient: 26 yo, female
Variant: VWF NM_000552.5 c:997+118 T>G g.(6073501 A>C), homozygous, intronic
Phenotypes: No detectable VWF in plasma, early onset bleeding complications, epistaxis, easy bruising, bleeding following injury, menorrhagia, iron-deficient anemia
Note: underwent prophylaxis replacement therapy, on-demand antihemorrhagic treatments, oral contraceptives, and replacement therapy.
Family: not mentioned
Predictions:
VEP SpliceAI tool predicted variant likely deleterious (delta score 0.95)
Used Polyphen-2 and SIFT which determined pathogenic likelihood.
Neural Network Splicing, Alternative Splice Site Predictor, plug-in MaxEnt(For 5' donor site) of Human Splicing Finder all concur this variant can create a new donor splice site in intron 8. Contains premature stop codon and susceptible to NMD.
Functional work:
qRT-PCR performed to identify levels of VWF in IP-derived endothelial cells.
histochemical immunostaining for IP-derived endothelial cells confirm no VWF production, only a residual amount present. Suggests leaky mutation.
performed RNA sequencing to assess co-regulated gene networks