[Usefulness of gray platelets observation in ARC syndrome].

Arthrogryposis Renal Fanconi syndrome and Cholestasis (ARC syndrome) is an extremely rare disease (62 cases) and is uneasy to diagnose. This congenital multisystem disorder affects newborns who usually die in the first year of life. The three cases here report the main clinical and biological features of this unknown disease and show how careful platelets morphology examination on blood smear can help for diagnosis. The three cases were observed at Robert Debré hospital in Paris over a twenty years period. In the first case, ARC syndrome was diagnosed after death. For the two following newborns, gray platelets detection in association with clinical symptoms allowed an earlier diagnosis.