Is transposition of the great arteries a consequence of maternal hormone imbalance? Evidence from the sex ratios of relatives of probands.

Transposition of the great arteries occurs more often to males than females: moreover there is reportedly an excess of males among the unaffected relatives of probands. This is construed as evidence that maternal intrauterine hormone levels play a role in the aetiology of this malformation. Copyright 1999 Academic Press.