Dermatoglyphic Evidence of Fluctuating Asymmetry in Schizophrenia

Abstract

Fluctuating asymmetry provides a measure of an organism's capacity to buffer adverse factors that could disturb its development. It is estimated from the differences between theoretically identical right- and left-sided structures. Dermatoglyphic fluctuating asymmetry has been recently used to investigate developmental disorders. Fingerprints and palm prints of schizophrenic patients, which had been the subjects of an earlier report of conventional dermatoglyphic trait frequencies, were reanalysed to determine their level of fluctuating asymmetry. A review of the diagnostic protocols and clinical records used in the original study indicated that most of the 482 subjects would have met DSM-III-R criteria for schizophrenia. The schizophrenic sample had significantly higher levels of fluctuating asymmetry on four dermatoglyphic traits, the finger-ridge counts, fingerprint patterns, the palmar atd angles and palmar a-b ridge counts, than controls. This finding supports the results of two earlier studies, and its relevance to the roles of genetics, foetal insults, and developmental anomalies of the brain in the aetiology of schizophrenia is discussed.

Fluctuating Asymmetry of Human Populations: A Review

“…Dermatoglyphic variables are either qualitative (patterns formed by dermal ridges and creases) or quantitative (counts of ridges or measurements of angles) [38]. The most common traits used for right-left asymmetry are finger and palmar ridge counts, palmar atd angles [1,81], ridge patterns on the fingertips, and palmar flexion crease patterns.…”

“…The authors found this approach to be more sensitive than traditional approaches to right-left asymmetry in a sample of schizophrenic patients. For ridge patterns (arches, radial loops, ulnar loops, and whorls), pattern discordance is used [38,86,87]. For example, if right and left index fingers both have the same ridge pattern (e.g., whorls on both fingers), then the patterns are concordant.…”

“…Consequently, claims that a greater frequency of, say, ulnar loops is associated with a particular physical anomaly, such as oral cleft, needs to be reexamined with more realistic degrees of freedom (see Mathew et al [92] for just one example). Similarly, tallying the numbers of discordant fingers over all homologous pairs inflates the degrees of freedom five-fold (see Mellor [38]). …”

“…Indices based upon the correlation coefficient [37], for example, and the related coefficient of indetermination [4,38], are the least powerful [8,39]. The correlation coefficient is strongly influenced by the range of observations.…”

Fluctuating Asymmetry and Steroid Hormones: A Review

“…Indeed, FA increases with exposure to chemical pollutants [7,8,[11][12][13][14], elevated predation risk [6,14,15], high population density [16,17], and ecosystem disturbances, including extreme temperatures in nonhuman animals [4,13,[18][19][20]. In humans, inbreeding [5], poor health conditions, and various neurological disorders, such as schizophrenia, attention deficit disorder, developmental delays in childhood, and Down syndrome are positively associated with FA [21][22][23][24][25].…”