RT Journal Article SR Electronic T1 Familial cerebellar ataxia presenting with down beat nystagmus. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 115 OP 118 DO 10.1136/jmg.17.2.115 VO 17 IS 2 A1 Schott, G D YR 1980 UL http://jmg.bmj.com/content/17/2/115.abstract AB Two brothers are described who during their fourth decade presented with isolated down beat nystagmus and later developed a progressive cerebellar ataxia. The nature of this unusual oculomotor disorder and its rare occurrence in other inherited conditions are discussed.