The excretion patterns of urinary glucosaminoglycans in a family with progressive familial myoclonus epilepsy.

The urinary excretion of uronic acid and the electrophoretic composition of urinary glucosaminoglycans were studied in 10 members of a family, of which 3 had progressive familial myoclonus epilepsy. This seems to be the first detailed investigation of the excretion of urinary glucosaminoglycans in patients suffering from this neurologic disease. The uronic acid excretion was found to be increased in the affected family members exclusively, whereas the excretion of the unaffected members were found within the normal limits characterized in this investigation. The urinary glucosaminoglycans could be separated into 5 fractions by electrophoresis. One or two of these fractions were increased in the urines of the three affected family members, the clinically most affected member showing the most abnormal electrophoretic results. An abnormal electrophoretic distribution of fractions was also found in the urines of 5 other members, clinically not affected. Only the maternal part of the family (mother and maternal grandmother) was shown to have a normal electrophoretic distribution of urinary glucosaminoglycans. The implication of these electrophoretic differences in the paternal and maternal family on the conditions for the development of the disease is discussed. The two fractions in question (designated fraction-0.65 and fraction-0.71) have until now been regarded as glycoproteins, but the present results show that they are true glucosaminoglycans (acid mucopolysaccharides), probably of low sulphate content.