Inheritance of congenital goitre due to a thyroid defection in Merino sheep

Abstract

An analysis of data from 599 Merino sheep has provided clear evidence that a condition of goitre, existing on 26 properties spread throughout the more closely settled parts of South Australia, is simply inherited. It is suggested that the condition is due to the action of an autosomal recessive gene whose action shows high penetrance and variable expressivity, and is accompanied by manifold phenotypic effects themselves equally variable in expression. This suggestion accords well with biochemical studies of goitrous sheep taken from among this sample. This study is continuing.