R. M. Gardiner

Prenatal diagnosis of Batten's disease

BACKGROUND Battens 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 Battens 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 Battens 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 Battens 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 Battens disease changes. INTERPRETATION We have successfully used direct gene analysis in the prenatal diagnosis of Battens disease.

Absence of Linkage of the Epithelial Sodium Channel to Hypertension in Black Caribbeans

Hypertensives of African origin have low-renin, sodium-sensitive blood pressure and respond poorly to treatment with angiotensin converting enzyme inhibitors. The epithelial sodium channel may be important in the pathogenesis of essential hypertension in this population. This is supported by the identification of mutations within this channel, which lead to excess sodium reabsorption and hypertension in Liddles syndrome. In this study we tested whether there was linkage of the genes encoding the three subunits of the epithelial sodium channel to essential hypertension in 63 affected sibling pairs of West African origin from St. Vincent and the Grenadines. We found no support for linkage of the epithelial sodium channel to essential hypertension in this population. However, further studies will be needed in larger populations of African ancestry to exclude a contribution of the genes encoding the epithelial sodium channel to hypertension.