[Prenatal diagnosis of X-linked adrenoleukodystrophy].

OBJECTIVE: To make prenatal dignosis of X-linked adrenoleukodystrophy (ALD) for the prevention of the disease.

METHODS: Eighteen amniocenteses were performed on 17 suspected carriers of X-ALD during 18-30 gestation weeks. The very long chain fatty acids (VLCFAs) levels of cultured amniocytes were tested by gas chromatography-mass spectrometry (GC/MS). The plasma VLCFAs levels were measured in 8 of the 18 prenatal diagnosed children when they were born or after abortion. ABCD1 gene mutation analysis was carried out in 8 cases by PCR and sequencing. ALDP of amniocytes was tested by Western blotting in 2 cases from a family, one female, another male, and the VLCFAs of cultured amniocytes were increased in both of them.

RESULTS: Among the 18 fetuses, 10 were males and 8 were females. The VLCFAs levels of the cultured amniocytes were increased in 3 males and 4 females. The postnatal plasma VLCFAs were normal in 5 cases with normal VLCFAs levels of amniocytes, and increased in 3 cases with high VLCFAs levels of amniocytes. ABCD1 gene mutations were found in 4 cases with high VLCFAs levels of amniocytes, no mutation was found in other 4 cases with normal VLCFAs levels of amniocytes. ALDP of amniocytes could be detected in the female with high VLCFAs levels of amniocytes, and it could not be detected in the male with high VLCFAs levels of amniocytes. Three male fetuses with high VLCFAs levels of amniocytes were aborted. The others who were born were normal clinically so far.

CONCLUSION: The prenatal diagnosis is very important for the prevention of ALD. Amniocyte VLCFAs level analysis combined with ABCD1 gene mutation analysis and ALDP test could make a proper prenatal diagnosis.