Congenital Factor XI deficiency in an elderly Japanese male accompanied by nonsense mutation p.Trp519* and novel missense mutation p.Ile618Phe

Key Points

• This case report aims to describe the genetic mutations associated with congenital Factor XI deficiency in a specific patient.
• Genetic analysis identified heterozygous mutations p.Trp519* and p.Ile618Phe in the patient.
• Measurements of factor XI activity were performed.
• The identified mutations resulted in decreased factor XI activity.
• Both mutations were classified as compound heterozygous.