This paper describes the progress of two previously reported brothers with familial glucocorticoid deficiency, achalasia of the cardia, and alacrima. In their early 'teens both boys developed polyneuropathy with sensory, motor and autonomic components, Parkinsonism, and signs of both dorsal column and pyramidal tract damage. The older boy also showed signs of dementia. Red cell folate levels were markedly reduced but plasma and CSF folate were normal. Serum B12 and erythrocyte concentrations were at or below the lower limit of normal CSF levels of homovanillic acid and 5-hydroxyindole acetic acid (the major metabolites of dopamine and serotonin in brain) were low, indicating impaired turnover of the two amines within the nervous system. Positron emission photometry scans in the older boy showed low binding of c-methyl-spiperone and reduced uptake of 18-F-L-fluorodopa in the striatum, confirming the impairment in dopamine metabolism and suggesting both reduced synthesis and reduced receptor density. Treatment with L-dopa up to 800 mg/day (along with carbidopa 200 mg/day) corrected the low CSF homovanillic acid levels and produced some improvement in the Parkinsonism but no other obvious clinical benefit. Empirical treatment with hydroxycobalamin (1000 micrograms three times a week) and folinic acid (15 mg/day) was without clinical effect. The cause of the neurological disorder, low red-cell folate concentrations, and amine disturbance remains unknown, as does the pathogenesis of the adrenocortical failure.