Adrenoleukodystrophy (ALD), the most frequent peroxisomal disorder, is
a severe neurodegenerative disease associated with an impairment of v
ery long chain fatty acids beta-oxidation. We have recently identified
by positional cloning the gene responsible for ALD, located in Xq28.
It encodes a new member of the ''ABC'' superfamily of membrane-associa
ted transporters that shows, in particular, significant homology to th
e 70-kDa peroxisomal membrane protein (PMP70). We report here a detail
ed characterization of the AT,D gene structure. It extends over 21 kb
and consists of 10 exons. To facilitate the detection of mutations in
ALD patients, we have determined the intronic sequences flanking the e
xons as well as the sequence of the 3' untranslated region and of the
immediate 5' promoter region. Sequences present in distal exons cross-
hybridize strongly to additional sequences in the human genome. The AL
D gene has been positioned on a pulsed-field map between DXS15 and the
L1CAM gene, about 650 kb upstream from the color pigment genes. The f
requent occurrence of color vision anomalies observed in patients with
adrenomyeloneuropathy (the adult onset form of ALD) thus does not rep
resent a contiguous gene syndrome but a secondary manifestation of ALD
. (C) 1994 Academic Press, Inc.