X-LINKED ADRENOLEUKODYSTROPHY - PHENOTYPE DISTRIBUTION AND EXPRESSIONOF ALDP IN SPANISH KINDREDS

X-linked adrenoleukodystrophy (X-ALD) is a neurodegenerative disorder caused by an impairment in peroxisomal beta-oxidation of very long str aight-chain fatty acids (VLCFAs), Six clinical phenotypes have been de lineated: childhood cerebral (CCALD), adolescent cerebral (AdolCALD), adult cerebral (ACALD), adrenomyeloneuropathy (AMN), Addison-only (AO) , and presymptomatic (PALD), The distribution of phenotypes varies in different countries. We have diagnosed biochemically 60 X-ALD Spanish patients belonging to 48 kindreds, Their phenotypic distribution was: CCALD plus AdolCALD, 33%; ACALD, 16%; AMN, 27%; AO, 12%; and PALD, 12% , These results contrast with the distribution described in other coun tries, due to a higher prevalence of the ACALD form, Regarding the exp ression of the protein product (ALDP), we studied 17 kindreds using im munochemical techniques and found absence of ALDP in 84% of cases, We also studied 13 females from 7 negative ALDP kindreds in order to corr elate ALDP expression and the carrier status established by VLCFA meas urement. In one case with normal VLCFA levels in serum and fibroblasts , we observed mosaicism in ALDP expression, This fact supports the use of this technique for identifying carriers. (C) 1998 Wiley-Liss, Inc.