[Onychoheterotopia with polyonychia associated with Pierre Robin syndrome: apropos of a new case. (Trial of classifying nail ectopia)].

The authors report the second case in the English language literature of a rare abnormality of the fingers and nails associated with Pierre Robin syndrome. The patient was born at term to non-consanguineous parents. The only potentially toxic drug taken by the mother during the first months of pregnancy was Sympathyl, a combined preparation of phenobarbitone, methenamine and plant extracts (boldo, crataegus) used as sedative. The child presented at birth with typical Pierre Robin syndrome responsible for respiratory distress, associated with hypotonia, dysplasia of the right hip and cardiac murmur. His development was marked by pronounced psychomotor retardation. At the age of four the patient was referred for congenital malformations of the hands, and notably bilateral and symmetrical abnormalities of the 5th finger consisting of inflammatory-like tapering, soft tissue hypotrophy, sucked appearance of the ungual phalanx, absence of palmar flexion folds and skin ridges and above all, presence of an ectopic supernumerary nail on the volar aspect of the ungual phalanx. This extra nail was not fused with the dorsal nail, although both met at their lateral edges. Other abnormalities were camptodactylia of the 4th fingers, clinodactylia of the 4th and 5th fingers and irreducible extension of the 5th fingers contrasting with hyperlaxity of their metacarpophalangeal joint. The karyotype (46 XY) was normal. Avulsion of the ectopic nails confirmed that they were distinct from the dorsal nails, having their own matrix.(ABSTRACT TRUNCATED AT 250 WORDS)