IDENTIFICATION OF GM2-GANGLIOSIDOSIS B1 VARIANT CARRIERS

GM2-gangliosidosis B1 variant, considered a rare disorder with a wide geographical and ethnic distribution, appears to be exceptionally freq uent in Portugal. In order to establish a carrier detection method for this disease we have determined the ratio of enzymatic activities aga inst 4MUGS and 4MUG in urine from B1 variant obligate carriers and con trols, using the total extract and the Hex A immunobound to a monoclon al antibody. The Hex A immunoassay was applied to the identification o f carriers in B1 variant families and the results obtained were compar ed with those from DNA analysis. The reliability and feasibility of th e Hex A immunoassay make it a suitable method for B1 variant carrier s creening, which is particularly important for the prevention of this s evere neurological disease in the population at risk.