This is a Wassel type-I pre-axial (radial) polydactyly: bifid (not duplicated) distal epiphysis. This type covers about 2% of all polydactylies, with type-IV being the commonest (40%). Phalanx duplication or polydactyly itself is type 3 under Swanson's classification of skeletal developmental conditions, which was subsequently adopted by relevant international societies.

The patient has not faced any functional difficulties including writing, hence the discovery is incidental. There is also no clinical evidence of any associated congenital anomalies. Nonetheless, the patient may still be advised a skeletal survey, followed by evaluation of other systems if necessary. 

In the absence of associated deformities and functional limitations, treatment of this deformity by surgical remodeling would depend on the patient's desire for cosmetic correction.