Plasma amino-acids in the Nigerian nutritional ataxic neuropathy.

Investigation of nine patients with tropical ataxic neuropathy showed an absence or diminution of sulphur-containing amino-acids-cysteine and methionine-and a variable concentration of most other essential amino-acids. The pattern was unlike that found in kwashiorkor. The levels of serum cholesterol and total protein were normal, and the serum vitamin B(12) levels were normal or high. Plasma thiocyanate concentration was high.All the patients gave a history of a monotonous diet of cassava derivatives. Cassava contains a cyanogenetic glycoside (linamarin) from which cyanide is released on hydrolysis. The excessive cyanide detoxication may be responsible for the low concentration of the sulphur-containing amino-acids.