Genetics and the epidemiology of leprosy. II. The form of leprosy.

Leprosy is made manifest i n a variety of forms and the classifica­ tion and relat ionships of these forms are matters of controversy . There is , however, wide agreement that communit ies vary i n the relative frequencies of the d ifferent forms of the d i sease and, further­ more, it i s accepted that the symptoms with in a part icular form of the d isease may vary i n d ifferent populations. I t has been shown in an earl ier paper, SPICKETT (1962); that there is a very great weight of evidence to support the hypothesi s that susceptibi l ity to some form of leprosy is cont rolled by a s ingle irregularly dominant gene. However in view of the characteristic forms of leprosy found in d ifferent popUlat ions i t seems possible that there m ight be a genetic control over the form of the d i sease . This paper is an attempt to see whether publ ished records can support this possibi l ity. Data concerning the incidence of forms of the disease have been publ ished by several authors using a variety of methods and termin­ ology of classification. S ince the relative val idit ies of the d ifferent schemes does not affect the present argument the terms used by the original authors have been used, rather than attempt to reclassify the data according to one system.