Dermatoglyphic patterns in dementia of the Alzheimer type: a case-control study.

STUDY OBJECTIVE: The aim was to compare digital and palmar dermatoglyphics in subjects with dementia of Alzheimer type and in mentally healthy elderly controls. DESIGN: This design was a case-control study. SETTING: The study was carried out in geriatric units and retirement communities in the Paris area. PARTICIPANTS: Cases were women with clinically diagnosed Alzheimer type dementia according to DSM III-R criteria (n = 82), mainly with late onset of the disease. Controls were women aged 85 years or older without cognitive deterioration (n = 76). MEASUREMENTS AND MAIN RESULTS: Finger and palm prints obtained from both hands by the classical ink method were examined. Fingerprints were classified into four types of figures. On palms, palmar flexion creases, palmar axial triradii, true patterns of the hypothenar area, and main line terminations were described. Examinations were performed by two examiners blind to the subjects's diagnostic category. For the different patterns studied, no major differences between dementia patients and elderly controls were found. Nor was there evidence of high frequencies of features commonly observed in Down's syndrome (trisomy 21), which have previously, though sporadically, been reported. CONCLUSIONS: On one of the largest samples of Alzheimer dementia patients studied, and with evaluation blind to diagnosis, no evidence has been found that particular dermatoglyphic patterns occur like those observed in Down's syndrome, a disease which is related to dementia of the Alzheimer type.

Dermatoglyphic patterns in senile dementia of Alzheimer's type.

Several reports suggest a genetic relationship between senile dementia of Alzheimer type (SDAT) and Down's syndrome. We have analyzed fingerprints and palmar patterns in an elderly female population comprising a group of 34 patients with probable SDAT, a group of 20 patients with other dementias, and a group of 20 non-demented controls. A bilateral Sydney line was found to be significantly more frequent in the SDAT group than in the two other groups (p less than 0.01, sensitivity 30%, specificity 95%, positive predictive value 91%, negative predictive value 61%). A bilateral Sydney line was as frequent in the SDAT group as in Down's syndrome. The limit value of the index of transversality equal or superior to 31, which is considered as a feature of Down's syndrome, was significantly more frequent in the SDAT group than in the two other groups (right hand p less than 0.05, left hand p less than 0.02). A bilateral discriminant value of this index was also significantly more frequent in the SDAT group than in the two other groups (p less than 0.02), as was an index of transversality higher than 31 on at least one hand (p less than 0.01). In contrast with other reports, we haven't found significantly different frequencies of digital ulnar loops and true hypothenar patterns between the SDAT group and the two others.