Relationship between genetic anomalies of different levels and deviations in dermatoglyphic traits. Part 4: Dermatoglyphic peculiarities of males and females with Down syndrome. Family study.

The present study was carried out in order to evaluate the effect of chromosomal morbidity (trisomy 21) in males and females with Down's Syndrome (DS) based on dermatoglyphic traits (DT) and their indices of diversity and asymmetry. The results were compared between parents and control groups of women and men whose data are detailed in our publication (Kobyliansky et al. 1999). The general aim of the study was to explore the possibility of using DT of the parents of DS patients to predict the likelihood of the disease appearing in the offspring. The samples were of DS patients (198 males and 140 females) and their parents (84 fathers and 153 mothers), all Israeli Jews. The prints were collected in the Genetic Institute of the Sheba Hospital, Ramat-Gan, Israel, and were validated by chromosomal examination. Interpretation of the prints was done according to Cummins & Midlo (1961) and Penrose (1968) and included identification of patterns, ridge counts and the measurements of distances and angles in the palm of the hands; 79 DT for every individual: 28 continuous traits, 9 discrete traits, 11 indices of intraindividual diversity (Div), 15 indices of directional asymmetry (DA) and 16 indices of fluctuating asymmetry (FA) were estimated. This study supports the hypothesis that the magnitude of FA in groups with low developmental stability (groups with chromosomal aberrations) or other birth defects, is elevated, compared with FA in healthy controls. The present study found proof of the existence of an additive genetic component in the FA of DT, while an increased FA was observed in parents of DS patients in comparison to control groups. The DT which are typical to DS patients were confirmed also in parents. The decrease in sexual dimorphism of the DT was found in DS patients and their parents in comparison with the control.