“…The same kindred was mentioned in 1875 by Charles Darwin. Subsequently, other investigators described clinically similar cases in a large number of families, thus creating the problem of their clinical and etiological delineation (reviews in Weech 1929, Touraine 1932and 1952, Upshaw and Montgomery 1949, Franceschetti 1953, Rosselli and Gulienetti 1961, Greene 1962, Montgomery 1967, Freire-Maia 1971, Bergsma 1973, Settineri 1974, Witkop et al 1975; see also Durham 1960, Rubin 1967, Jablonsky 1969. Cardinal signs, associated signs and general symptoms have been recognized; severe, moderately severe, and mild states have been identified; "incomplete syndromes " and " variants " have been described.…”