HYPOTHESIS - ONE CAUSE OF POLYDACTYLY

The strongly male-biased sex ratios of probands with polydactyly and o f their unaffected sibs suggests that abnormal maternal hormone levels may be involved in this malformation. This suspicion is supported by data relating polydactyly to maternal age and race. High maternal test osterone seems capable of explaining the (admittedly limited) epidemio logical data on polydactyly. If this were so, one may predict that off spring risk would be higher in respect of affected mothers than affect ed fathers. (C) 1998 Academic Press.