Dystelephalangy

Description

Kirner deformity, or dystelephalangy, is a rare malformation of the fifth finger that consists of radial bowing of the terminal phalanx, with the tip of the finger pointing toward the thenar eminence. The deformity is usually bilateral (summary by Temtamy and McKusick, 1978).

Clinical Features

Dykes (1978) reported 12 cases of Kirner deformity (10 females, including 4 sisters, and 2 males) and reviewed reported cases. The usual feature of the condition was bilateral palmar and radial curvature of the tip of the little finger, developing spontaneously just before puberty without pain or other abnormalities. Radiographs showed that the deformity is the result of tilting of the terminal diaphysis, which, for a period, is thin and dense.

David and Burwood (1972) found no association between congenital heart disease and Kirner deformity.

Temtamy (1986) suggested that the deformity of the fifth finger in Russell-Silver syndrome (180860) is Kirner deformity, not brachymesophalangy V.

Inheritance

Autosomal dominant inheritance of dystelephalangy with incomplete penetrance is supported by the findings of Blank and Girdany (1965), Brailsford (1953), Wilson (1952), and David and Burwood (1972).

Population Genetics

David and Burwood (1972) surveyed a selected population form the southwest of England, finding 18 cases of dystelephalangy in 9 families. The incidence in the general population was 1 in 410. There were 12 affected females and 6 affected males: bilateral deformity was heavily favored in the females and unilateral deformity in the males.

History

Kirner deformity was first described by Kirner (1927). The term dystelephalangy was first used by Sugiura et al. (1961).