Dominant Spastic Ataxias

Spastic ataxias are ataxias that have spasticity (muscle stiffness) in addition to ataxia. Some types of spastic ataxias are dominant and some are recessive. The dominant forms are described below, while the recessive forms are discussed later in this booklet. The acronym SPAX is used to name some of these ataxias (SPastic AtaXia).

SPAX1
SPAX1 is a type of dominant spastic ataxia that has so far been described in families from Newfoundland and Iran. The spasticity (muscle stiffness) primarily affects the legs. Symptoms begin in adulthood (50’s) in the family from Iran, while symptoms began between ages 10-20 in the family from Newfoundland. The gene that causes this condition has not yet been identified.