The effect of absence of thumb on palmar dermatoglyphics.

When a hand has no thumb ridge configurations in the proximal palm are distorted. There is no axial triradius, and the ridges run transversely across the palm. This unusual arrangement was reported in German cases of thalidomide poisoning by Pfeiffer and zu Berge (1964). Since that time the characteristic alignment has been found not only in English cases of thalidomide poisoning with radial dysplasia, but in similarly deformed hands of patients with varying chromosomal aberrations. Fig. 1 shows the right hand of an English case of thalidomide poisoning. There is no thumb, but all the other digits are present. The axial triradius is absent and the alignment of the ridges in the proximal part of the palm is transverse. On this palm the courses of the main lines B, C, and D are anomalous; all terminate on the radial border. This peculiarity is not found in all cases of radial dysplasia. However, such an arrangement is not uncommon on the hands of children suffering from thalidomide poisoning. The hands of another case of thalidomide poisoning are shown in Fig. 2. On both the thumb is missing and the characteristic transverse orientation of the ridges in the lower sections of the palms is apparent. On the right hand there is an ulnar triradius associated with a radial loop. Only 3 fingers are present on the left hand and the only triradii on the palm are 2 interdigital ones. Both hands show the radial direction of the main lines, as in Fig. 1. Fig. 3 shows the hands of another child suffering from thalidomide poisoning. The left hand is normal with all 5 digits and there is nothing anomalous