Exon 2 Skipping Eliminates Γ‐glutamyl Carboxylase Activity, Indicating a Partial Splicing Defect in a Patient with Vitamin K Clotting Factor Deficiency

Unlabelled BoxEssentials•A carboxylase mutation that impairs splicing to delete exon 2 sequences was previously reported.•We found that the mutant was inactive for vitamin K‐dependent (VKD) protein carboxylation.•An incomplete splicing defect likely accounts for VKD clotting activity observed in the patient.•The results indicate the importance of proper carboxylase embedment in the membrane for function.