Aim: To develop a DNA-based diagnostic test for adrenoleukodystrophy (ALD) in a large New Zealand family.
Methods: Mutation screening of the X chromosome-linked ALD gene was undertaken by direct sequencing of PCR amplified products encompassing defined exons of the ALD gene. The identification of a mutation led to the development of a simple restriction enzyme digestion protocol of a PCR amplified product to identify those individuals with the mutation.
Results: A nonsense mutation, resulting in deduced premature termination of translation of the ALD gene product, was detected in exon 4 of the ALD gene in an affected male. This mutation was found in three obligate gene carriers in the same ALD family. A DNA-based test was established to identify this mutation by Bgl II digestion of a PCR amplified product encompassing exons 3 and 4 of the ALD gene. The DNA-based test was applied to a chorionic villus sampling for prenatal diagnosis.
Conclusions: A simple DNA-based test has been developed for ALD in a large New Zealand family. This test provides a rapid means of determining carrier status and for undertaking prenatal diagnosis for ALD in this family.