Nettleship's two pedigrees of retinitis pigmentosa: a historical postscript

Two pedigrees of retinitis pigmentosa, originally published by Nettleship, are presented with extracts from his private correspondence. Affected descendants from the two families have been traced, in one family extending the pedigree to nine affected generations, and in the other providing an instance of male-to-male transmission in a pedigree previously considered as being possibly X-linked.