Hereditary Anchylosis of the Proximal Phalangeal Joints (Symphalangism).

Various types of developmental malformation of the hands and feet have been described under such terms as polydactylism, syndactylism, brachydactylism, ectrodactylism, macrodactylism, hyperphalangia and hypopha1angia.l Familial tendencies have been recognized in the case of some of these anomalous conditions, but the first definite record showing that one of them is a unit-character inherited in accordance with Mendelian laws was made in 1905 by WM. C. FARABEE. His recorded family were residents of Pennsylvania and in the affected members there occurred a shortening of the fingers and toes which possessed only one instead of two interphalangeal articulations ( hypophalangia or brachydactylism) . Subsequently DRINKWATER ( 1908) described an English family which had exhibited the same dominant character through seven generations. The affected persons in both FARABEE’S and DRINKWATER’S families, which were possibly related, possessed a notably shortened stature, so that probably more than one abnormal unit-character was concerned. Still another type of familial malformation had been previously described by WALKER (1901) as a particular form of anchylosis involving more especially the midphalangeal joints. The number of his recorded cases was too small to justify any conclusions on a Mendelian basis, though the malformation, the degree of which varied considerably in the different individuals, had been transmitted through five generations. In one of the cases there was an actual loss of the terminal phalanges of the two postaxial (ulnar) fingers, but otherwise there were no abnormalities aside from the aforementioned anchylosis. This paper will present a