Fingerprint patterns in Alzheimer's disease.

Fingerprint dermatoglyphic patterns in 50 patients with presumed senile dementia of the Alzheimer type (SDAT) were compared with a control group of 50 patients with other neurologic diseases and with population norms. Patients with SDAT showed a significantly increased frequency of ulnar loops on their fingertips and a concomitantly decreased frequency of whorls and arches. A pattern of eight or more ulnar loops was found significantly more often in patients with SDAT (72%) than in the control group (26%). Fourteen patients with SDAT had ulnar loops on all ten fingers; this occurred in four patients in the control group. Radial loops on the fourth and fifth digits were more prevalent in patients with SDAT. The fingerprint patterns observed in patients with SDAT are congruent with patterns repeatedly found in Down's syndrome, and support the known associations between these two diseases at a further level.