Background: Batten's disease is the most common progressive encephalopathy of childhood in Western countries. The major mutation is a 1kb deletion, which is carried by 81% of Batten's disease patients. We report on the use of direct gene analysis in the prenatal diagnosis of this disease.
Methods and findings: A Finnish woman with a son with Batten's disease came for genetic counselling for her current pregnancy. Electron microscopy of a chorionic villus sample gave suggestive findings. We used PCR to look for the intragenic microsatellite marker D16S298; 96% of Finnish Batten's disease patients carry allele 6 at this marker. The fetus and the affected son both carried the same high-risk genotype, 6/6. Both were homozygous for the 1 kb deletion. The pregnancy was terminated. Electron microscopy of the fetus showed typical Batten's disease changes.
Interpretation: We have successfully used direct gene analysis in the prenatal diagnosis of Batten's disease.