ABCB7 is essential in mice [30], and in humans, ABCB7 mutations cause X-linked sideroblastic anemia and ataxia (XLSA/A), a rare disorder characterized by an early-onset of non- or slowly progressive spinocerebellar ataxia and mild to moderate anemia [31]. This evidence concerns the gene ABCB7 and X-linked sideroblastic anemia with ataxia.