Abstract
The incidence of institutional samples and the frequency of birth of mongolism is mentioned. A brief review of hypotheses concerning the possible etiology and genetic factors which may be implicated in this disorder. Mention is made of the appearance of microsymptoms in relatives with particular reference to dermatoglyphic patterns. The difficulty of making objective measurements of some of the associated defects is noted. The work of Ingalls on the temporal aspects of the growth disturbances is mentioned. Lowe's observations on the characteristic lens opacities and speckled irides and his suggestion that an underlying vascular disturbance is likely to be responsible for these findings are noted. Attention is drawn to his observation of the rarity of defects which would suggest disturbance during the organo-genetic period. A suggestion is made that the causation of mongolism must be temporarily extended over a considerable period of foetal development, and Penrose's postulate for foetal requirements of “x” substance is quoted.
Experiments with maternal avitaminosis are mentioned. It is suggested that there may be disturbance of growth due to abnormalities in transfer of substances to and from the capillary system to the surrounding tissue fluids. It is suggested that the so-called hypertrophic fungiform papillae of the tongue are a post-natal development due to localized oedema and it is postulated that this may be associated with capillary abnormalities. A clinical observation that petechial haemorrhages occur readily in mongolian children is noted and the results of an experiment measuring the resistance of the capillary wall to negative pressure is described. The results of these experiments demonstrate a significant reduction in capillary resistance in male and female institutionalised mongols and some suggestions are made as to further studies.