Pagon syndrome: Congenital anemia with spinocerebellar ataxia (wobbliness). The anemia is characterized by sideroblasts (iron-rich ancestors of red blood cells). The spinocerebellar ataxia becomes evident by 1 year of age.
The syndrome is inherited in an X-linked recessive manner and is due to mutation in the ABC gene in Xq13.1-q13.3. The ABC gene is an ATP-binding cassette (ABC) transporter, encodes a protein that localizes to the mitochondrial inner membrane and is involved in iron homeostasis. Thus, Pagon syndrome is a mitochondrial disease caused by a mutation in the nuclear genome.