Pair of Dizygous Twins of Consanguineous Parents*

The classical form of amyotrophic lateral sclerosis (ALS) or Charcot's disease contains both familial and sporadic cases. The familial form has been extensively reviewed by Faveret (1959), Haberlandt (1964), and Becker (1966). Sporadic cases present the same clinical features. In addition, there is a form of the disease encountered in the native inhabitants of Guam and Japan. It displays several clinical signs and pathological lesions identical to those of the classical form, and yet it shows differences concerning epidemiology, age of onset, and sex ratio (Hirano et al., 1967; Yase, 1966; Kurland, 1965). The two patients to be presented show the clinical features of the classical type of ALS. Though nosologically unremarkable, they are of interest because they are dizygotic twins and the products of a consanguineous marriage.