HM Cakmak

Abstract

Purpose: To describe the clinical, laboratory, genetic, and familial features of a child with mild factor X deficiency and associated multisystem findings. Methods: A 6-year-old boy with daily epistaxis underwent coagulation testing, family evaluation, pedigree analysis, and exome sequencing. Findings: Prothrombin time was prolonged, activated partial thromboplastin time was normal, and factor X activity was 20.3%. The father and sister also had prolonged prothrombin time, supporting familial inheritance. Exome sequencing identified a novel heterozygous F10 variant, F10 (NM_000504.4):c.785G>A, p.(Gly262Asp), classified as likely pathogenic. Additional variants were detected in DMGDH, TRPA1, and TNFRSF13B, correlating with fish-like odor with muscle fatigue and familial episodic pain. No immunological work-up, including serum immunoglobulin measurements, was available in this report; therefore, the TNFRSF13B finding was interpreted cautiously and was not considered diagnostic of CVID or another primary immunodeficiency. Pedigree analysis showed recurrent bleeding and episodic pain on the paternal side. Conclusions: This case expands the molecular spectrum of F10-related disease and supports exome-based evaluation in families with bleeding and multisystem phenotypes when routine coagulation studies and family history suggest a broader inherited disorder in affected relatives.