A novel homozygous frameshift mutation (p.Lys365Glnfs*69) in a family with hereditary factor XII deficiency: a case...

Area of Science:

• Genetics
• Hematology

Background:

• Factor XII (FXII) deficiency is a rare autosomal recessive disorder.
• It is characterized by prolonged activated partial thromboplastin time (APTT) but typically lacks a bleeding tendency.
• Genetic diagnosis is crucial to prevent unnecessary medical interventions.

Purpose of the Study:

• To investigate the genetic basis of Factor XII deficiency in an 8-year-old boy with an incidentally discovered prolonged APTT.
• To confirm the mode of inheritance and expand the understanding of F12 gene mutations.

Main Methods:

• Biochemical assays to measure FXII activity.
• Genetic testing to identify mutations in the F12 gene.
• Familial segregation analysis to confirm inheritance patterns.

Main Results:

• The patient presented with a significantly prolonged APTT (>170 s) and low FXII activity (7.7%).
• Genetic analysis revealed homozygous F12: c.1092dup mutations, inherited from both parents.
• Segregation analysis confirmed an autosomal recessive inheritance pattern in the family.

Conclusions:

• The identified F12: c.1092dup mutation is associated with Factor XII deficiency.
• This case underscores the importance of genetic diagnosis for FXII deficiency to guide clinical management and avoid unnecessary procedures.