Alpha-fetoprotein as a biomarker for recessive ataxias.

MD, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo SP, Brazil; MD, PhD, Department of Neurology and Neurosurgery, UNIFESP. Alpha-fetoprotein (AFP) is a fetal protein produced in the yolk sac and in the fetal liver. AFP has been implicated in both ontogenic and oncogenic growth disorders. Although the main biologic role of AFP during pregnancy remains controversial to this day, AFP has been related to fetal birth defects and tumors. AFP is recognized as one of the first tumor markers. It was first associated with hepatocellular carcinomas and later to germ cell tumors. The autosomal recessive ataxias, including ataxia-telangiectasia (AT) and ataxia with oculomotor apraxia type 2 (AOA2), belong to a special group of hereditary ataxias with heterogeneous presentation. Simple laboratory studies, like AFP measurement, have been reported to be helpful in the differential diagnosis of ataxias. The purpose of this review is to describe the association of serum AFP with recessive ataxias. We report the clinical and laboratory findings of three patients with a recessive ataxia profile.