The hand pattern profiles of 18 previously published and 10 new cases of de Lange syndrome were compared to those of cases referred as suspects, but judged clinically and by numerical taxonomic methods not to have de Lange syndrome (non-de Lange). Based on a Poznanski metacarpophalangeal profile of the 2 groups of patients, a simple scoring system using 11 measurements was devised using the 16 most marked differences within and between metacarpals and phalanges. Of the metacarpals, the first is shorter than the second, third, fourth, or fifth; and the second and fifth are shorter than the third or fourth. Of the middle phalanges, the third and fourth are shorter than the respective metacarpal and than the second and fifth middle phalanx. Of the distal phalanges, the fifth is shorter than the second. The mean Z score for these 11 measurements is further below normal in the de Lange group than in the non-de Lange group. All 11 non-de Lange patients had a score less than 17, and all 28 de Lange patients had a score of 18 or more.