Three adult patients from one family with late-onset Friedreich’s ataxia (LOFA) presenting after 25 years (mean age, 30 yrs) were compared with 13 children with classical FA presenting before 20 years (mean age, 13 yrs) and reported from the University of Tubingen, Germany, and St Mary’s Hospital, London, England. Clinical presentation of LOFA and FA were similar, except that muscle wasting, foot deformity, and cardiomyopathy were absent in LOFA patients. Genetic linkage analysis using markers tightly linked to the FA locus on chromosome 9 showed that all affected members of the LOFA family, but not their unaffected siblings, had inherited identical paternal and maternal genotypes. LOFA may result from mutation within the FA locus, giving rise to a more benign and slowly progressive disorder. [1]

COMMENT. With the exception of age of onset, all patients with LOFA satisfied the basic diagnostic criteria for classical Friedreich’s ataxia: 1) progressive ataxia; 2) family history with autosomal-recessive inheritance; 3) loss of tendon reflexes in lower limbs; 4) dysarthria; and 5) posterior column signs. The more benign ‘Acadian’ subtype (Barbeau et al, 1984) has previously been differentiated from the classical, French and French Canadian, type of FA and has been attributed to a mutation at the same locus. [2]