Abstract
Congenital myelofibrosis (cMF) is a rare inherited bone marrow failure disorder. We report a 26-year-old Chinese male with a 24-year history of recurrent epistaxis and thrombocytopenia. Laboratory findings revealed severe thrombocytopenia (18 × 10⁹/L) and bone marrow biopsy showed MF-3 fibrosis with impaired megakaryopoiesis. Genetic analysis identified a novel homozygous nonsense mutation in MPIG6B (c.420T > A, p.Y140X), leading to a diagnosis of cMF. This case expands the clinical spectrum of MPIG6B-related disorders and illustrates the long-term natural history in a non-consanguineous population. The patient achieved clinical stability with eltrombopag and danazol.