Rare Inherited Coagulation Deficiencies: A Single-center Study.

Background: Rare factor deficiency (RFD) is characterized by a deficiency of factor (F)I, FII, FV, FVII, FX, FXI, FXII, FXIII, or a combined deficiency of FV+FVIII or vitamin K-dependent factors. The prevalence of RFD ranges from 1/1,000,000 to 3,000,000. Combined deficiencies of vitamin K-related factors have been described in 30 families worldwide, and these patients can present with a wide range of clinical symptoms, from mucocutaneous bleeding to life-threatening symptoms such as central nervous system and gastrointestinal bleeding.

Objective: This study aimed to contribute to the literature on RFD.

Material and methods: This retrospective study analyzed data from 43 children with RFD.

Results: The most common factor deficiencies were FVII (n=13); whereas the other deficiencies were FI (n=1), FV (n=2), FV+FVIII (n=2), FX (n=6), FXI (n=5), FXII (n=9), FXIII (n=3), and vitamin K-dependent combined factor deficiency (n=2). Acute and severe bleeding was controlled by treatment in 6 patients, and 12 patients with recurrent bleeding symptoms received prophylaxis. RFDs were more common in regions with high rates of consanguineous marriage, and in our study, 16 (16/43) of the cases were found to have consanguineous marriages between parents.

Conclusions: It is important to improve genetic counseling and access to testing for family members with RFD due to autosomal recessive inheritance. Delays in diagnosis and treatment and lack of adequate prevention are important risk factors for life-threatening bleeding.