| A rare syndromic inherited form of sideroblastic anemia characterized by mild to moderate anemia (with hypochromia and microcytosis) and early-onset, non or slowly progressive spinocerebellar ataxia. Caused by mutations in the ABCB7 gene (Xq13.3), encoding a mitochondrial ATP-binding cassette (ABC) transporter protein, which plays a role in heme production and iron homeostasis. A mutation in this gene alters the availability of reduced iron and therefore disrupts heme biosynthesis. The ABCB7 gene is highly expressed in both the bone marrow and the cerebellum, which may explain ataxia. Inherited in an X-linked recessive manner. |
