Cretinism
Congenital hypothyroidism (underactivity of the thyroid gland at birth) resulting in growth retardation, developmental delay and other abnormal features.
Can be due to deficiency of iodine in the mother's diet during pregnancy.
The condition is detected today by newborn thyroid screening.
The word 'cretin' is said to have come from the Old French 'chretien' meaning 'Christian' because heretical Christians, to escape persecution, fled into iodine-deficient valleys in the Pyrenees in southwest France and had children with congenital hypothyroidism.
However, the origin of the term 'cretin' is conjectural and could come from 'cretura' (creature) or 'creta' (chalk, pale) or some other root.