To carry out prenatal diagnosis on two fetuses of different pedigrees with X-linked adrenoleukodystrophy (ALD).The amniotic fluid was obtained with the help of a clinical doctor and the genomic DNA was isolated from it. Maternal DNA contamination was excluded by fluorescent STR profiling, The R617G mutation found in the first pedigree was searched in genomic DNA of amniotic fluid cells (AFC) from fetus 1 by amplification refractory mutation system (ARMS) and dot DNA hybridization while the P534R mutation found in pedigree 2 was analyzed in the AFC genomic DNA of fetus 2 by restrictive digestion with Hae II and DNA direct sequencing.A specific band (185 bp) was detected from the genomic DNA of the first fetus and his mother by using mutation primer in ARMS but not from that of the first fetus's father and unrelated controls. DNA dots were visualized only in the fetus 1 and carrier when using the mutation probe in DNA hybridization. In the other ALD family, the PCR product (506 bp) of the second fetus which spanned the site of P534R mutation could not be digested with Hae II and no mutation was detected in the ABCD1 gene from the genomic DNA of the fetus 2 by using DNA direct sequencing.Fetus 1 had R617G mutation on his ABCD1 gene and he was an adrenoleukodystrophy hemizygote. Fetus 2 had no P534R mutation on his ABCD1 gene and he was a normal hemizygote.