Total submissions: 1
Submitter | RCV | SCV | Clinical significance | Condition | Last evaluated | Review status | Method | Comment |
---|---|---|---|---|---|---|---|---|
Kids Neuroscience Centre, |
RCV001726510 | SCV001571526 | pathogenic | Long QT syndrome 2 | criteria provided, single submitter | clinical testing | mRNA studies establish the KCNH2 c.2399-28delA variant leads to loss of the long isoforms of KCNH2 from t paternal allele in blood RNA. The mechanism for mis-splicing is likely due to loss of the only available branchpoint adenosine for intron branching, which is required for excision of the intron-9 lariat and ligation of exon 9 and exon 10. There are several pathogenic variants associated with Long QT syndrome reported in Clinvar in exons 10-15 of KCNH2 that affect only the long isoforms of KCNH2. And, loss-of-function variants are a known pathogenetic mechanism in Long QT syndrome. Therefore, haploinsufficiency of long isoforms of KCNH2 due to the c.239928del variant is consistent with the known pathogenetic mechanism in Long QT syndrome. |