Method: The activity and amount of SOD1 in erythrocyte lysates and the plasma amino acid content were evaluated in four familial ALS patients bearing the L84F SOD1 mutation (fALS), in an asymptomatic family member with the mutation (L84F5), in sporadic ALS patients (sALS) and controls. Three of the fALS patients and the L84F5 subject were tested once a year for three consecutive years. Results: At the first evaluation SOD1 activity was similar in controls, sALS and fALS; the amount of SOD1 protein was lower (P <0.01) in fALS. In the subsequent 2 years, 34% and 52% decrease of SOD1 activity was recorded in fALS patients. The plasma amino acid pattern did not differ between controls and sALS, whereas fALS patients displayed high levels of plasma aspartate and glutamate. Aspartate was in the normal range but glutamate was still elevated in the subsequent evaluations. The L84F5 subject had remarkably low levels of aspartate, glutamate and branched-chain amino acids. Conclusions: The method of measuring mutant SOD1 amount is indirect but the results are indicative of a reduction of mutant SOD1 taking place during fast-worsening phases of the disease. Since the disease onset of fALS patients is 42.8 ± 11.3 years and the L84F5 family member is asymptomatic at the age of 66, low levels of excitotoxic and branched-chain amino acids in plasma may constitute a protective factor against disease development.
|Number of pages||8|
|Journal||Amyotrophic Lateral Sclerosis and Other Motor Neuron Disorders|
|Publication status||Published - Sep 2002|
- Amino acids
ASJC Scopus subject areas
- Clinical Neurology