Talk to the Hand: Finger and Hand Palm Prints in Adolescents with ASD As Compared to the General Population

Background: Dermatoglyphics are the ridge constellations found on the hand palms and foot soles that are permanently formed by the 24^th week of pregnancy. Syndromes such as Down’s syndrome or fragile-X syndrome are associated with irregularities in finger and hand palm prints and ridge counts. Developmental stability reflects the individual’s resilience to stress in the (prenatal) environment. Developmental instability represents the degree to which a person’s developmental path is disturbed by exogenous factors. Dermatoglyphic patterns are sometimes used as proxy markers of prenatal instability. The underlying idea is that certain brain developments take place at the same prenatal time period, and from the same ectoderm, as dermatoglyphic development does, such as the formation of the ridges on the hands and feet. Developmental instability is usually measured by deviations from perfect symmetry of bilateral traits, such as for instance dermatoglyphics. When genetic or environmental disturbances occur, an organism has a natural capacity to repair this and go back to its original developmental path. The stronger this capacity is the lower the left-right differences (also called fluctuating asymmetry) and the higher the developmental stability. 

Objectives: Data from dermatoglyphics in relation to ASD are limited, conflicting and very old. In the last few decades, the prevalence of ASD has shown a rapid rise, particularly of higher functioning forms of ASD. It would therefore be useful to repeat the older studies in a more contemporary sample of adolescents with ASD. The aim of this study therefore is to compare the hands of teenagers with ASD, with ‘normal controls’ and with ‘psychiatric controls’ on different dermatoglyphic variables. We hypothesize that adolescents with ASD, as compared to the other two groups will show a) a higher rate of fluctuating asymmetry, b) a lower ridge count on the finger tips, c) a lower ridge count on the hand palms, d) more deviances in the palmar flexion crease, and e) a larger atd-angle.    

Methods: A large number of dermatoglyphic variables is examined in this study; finger tip patterns (whorls, loops or arches), finger ridge counts (FRC), hand palm ridge counts (a-b, b-c, c-d), atd-angle and the type of palmar flexion crease (normal, Simian or Sydney). Asymmetry of these variables between the left and the right hand is examined. A group of adolescents with ASD’s (n = 50) is compared to a group of adolescents from the general population (n = 50) and to a clinical control group of adolescents with other psychiatric disorders (n = 20). A DSM-IV classification of ASD is confirmed by ADI-R and ADOS-G assessment.  

Results: Results are currently being analyzed. They will be available from January 2012. Therefore application for poster presentation is made (not oral).  

Conclusions: Conclusions will be available from February 2012. Therefore application for poster presentation is made (not oral).