GENETICS OF PRIMARY ALDOSTERONISM

1. In 1991 we described a familial variety of primary hyperaldosteroni sm which was not glucocorticoid-suppressible and was associated with a denoma formation, and called it familial hyperaldosteronism type II (F H-II) in order to distinguish it from the glucocorticoid-suppressible variety described in 1966, familial hyperaldosteronism type I (FH-I). 2. In 1992 the genetic basis of FH-I was clarified by description of a hybrid gene. 3. Primary aldosteronism due to bilateral adrenocortical hyperplasia or to aldosterone-producing tumour can be part of the mul tiple endocrine neoplasia type I syndrome (MEN I), in which loss of he terozygosity has been described on chromosome 11q13. Loss of heterozyg osity at the MEN I locus was found in five of 26 aldosterone-producing tumours from our series (by Japanese collaborators). These included t wo with adrenal cancer and two with FH-II. 4. We recently described an association of aldosterone responsiveness of aldosterone-producing ad enomas with renin gene restriction fragment length polymorphisms, sugg esting a possible role for renin genotype and intra-adrenal renin gene expression in the development and biochemical expression of some aldo sterone-producing tumours. 5. We found abnormal karyotypes in 13 of 32 benign aldosterone-producing adenomas.