Three small and severely retarded girls lack the nail and terminal phalanx of the little finger. The nails and distal phalanges of the lateral toes are hypoplastic or missing. Many other anomalies are present. There are no other affected persons in the families, and the cause of the syndrome has not been found.
Coffin GS, Siris E. Mental Retardation With Absent Fifth Fingernail and Terminal Phalanx. Am J Dis Child. 1970;119(5):433-439. doi:10.1001/archpedi.1970.02100050435009