Venous thrombosis affecting thrombocytopenic patients is challenging. We report the case of a woman affected by deep vein thrombosis and pulmonary embolism in a thrombocytopenic context leading to the discovery of a heterozygous mutation in the gene encoding ankyrin repeat domain 26 (ANKRD26) associated with a heterozygous factor V (FV) Leiden mutation. This woman was diagnosed with lower-limb deep vein thrombosis complicated by pulmonary embolism. Severe thrombocytopenia was observed. The genetic study evidenced a heterozygous FV Leiden mutation. Molecular study sequencing was performed after learning that her family had a history of thrombocytopenia. Previously described heterozygous mutation c-127C>A in the 5'untranslated region (5'UTR) of the ANKRD26 gene was detected in the patient, her aunt, and her grandmother. ANKRD26-related thrombocytopenia and thrombosis are rare. This is, to our knowledge, the first case reported in the medical literature. This mutation should be screened in patients with a family history of thrombocytopenia.