Although maternal age has been abundantly sustained as a factor in the causation of mongolism,1 of the polydactylism of guinea pigs2 and of congenital malformations,3 no reference has yet appeared relating to the possible role of this factor in the causation of achondroplasia.
It was hard to obtain records of maternal age at the time of birth of achondroplastic children in sufficient numbers to be worthy of study. Most of the patients who might have provided such information had been lost sight of, and, more often than not, no record of their mother's age appeared in their histories.
In the available articles on achondroplasia among the four hundred and ninety-six which appeared in the literature up to July 1938, there were reported only 47 cases in which the age of the mother was recorded or could be secured by correspondence with the author. It therefore became necessary