THE R496H MUTATION OF ARYLSULFATASE-A DOES NOT CAUSE METACHROMATIC LEUKODYSTROPHY

Deficiency of arylsulfatase A (ARSA) enzyme activity causes metachroma tic leukodystrophy (MLD). A number of ARSA gene mutations responsible for MLD have been identified. Recently, the R496H mutation of ARSA was proposed to be a cause of MLD (Draghia et al., 1997). We have investi gated the R496H mutation and found this mutation at a relatively high frequency in an African American population (f = 0.09, n = 61 subjects ). The ARSA enzyme activity in subjects with and without the R496H mut ation was determined and found to be normal. It is therefore concluded that the R496H mutation of ARSA does not negatively influence the act ivity of ARSA and is not a cause of MLD. Hum Mutat 12:238-239, 1998. ( C) 1998 Wiley-Liss, Inc.