Dermatoglyphic sole patterns in 21 trisomics

Frequencies of loop patterns on the proximal sole have been estimated in the sample of 21 trisomic subjects and compared with those previously obtained in a sample of normal individuals. Results indicate that, in Down's syndrome, a lowered pattern intensity, characteristic of the distal sole does not occur on the proximal sole. Studies of patterns on the proximal portion of the sole should be pursued using larger samples of 21 trisomics, providing that care is taken to obtain the best quality footprints; the main limitation in such studies is in the common occurrence of ridge dissociation. In addition, some previous estimates of the frequency of zygodactylous triradii on the distal sole have been reconsidered on the basis of the results obtained in the present sample of footprints with complete recording of areas under the toes.