Dermatoglyphics

Dermatoglyphics (from Ancient Greek derma, "skin", and glyph, "carving") is the scientific study of fingerprints, lines, mounts and shapes of hands. Dermatoglyphics refers to the making of naturally occurring ridges on certain body parts, namely palms, fingers, soles, and toes. These are areas where hair usually does not grow, and these ridges allow for increased leverage when picking up objects or walking barefoot. The fingerprints of both hands are not the same. They do not change size or shape throughout a person's life, except in cases of serious injuries that scar the dermis.

As a term, dermatoglyphics is used to distinguish it from the superficially similar pseudoscience of palmistry. Recently, the scientific basis underlying dermatoglyphics was questioned by the National Academy of Sciences in a 2009 report^[1] for relying on subjective comparisons instead of conclusions drawn from the scientific method.

Dermatoglyphics and genetic aberrations

Dermatoglyphics, when correlated with genetic abnormalities, is useful in the diagnosis of these disorders at birth or soon after. They aid in the diagnosis of congenital malformations.

• Klinefelter syndrome: excess of arches on digit 1, more frequent ulnar loops on digit 2, overall fewer whorls, lower ridge counts for loops and whorls as compared with controls, and significant reduction of the total finger ridge count.^[2]
• Cri du chat (5p-): abnormal dermatoglyphics are associated with 92% of patients in a critical review of multiple studies,^[3] including single transverse palmar creases and triradii in the t' position on both hands.^[4]
• Congenital blindness: Initial data points to abnormal triradius.^[5]
• Naegeli–Franceschetti–Jadassohn syndrome: patients lack dermatoglyphics of any kind.^[6]
• Noonan syndrome: increased frequency of whorls on fingertips, and the axial triradius t, as in Turner syndrome, is more often in position t' or t" than in controls.^[7] Increased incidence of the single transverse palmar crease.
• Trisomy 13 (Patau syndrome): excess of arches on fingertips and single transverse palmar creases in 60%.^[8] Additionally, the halucal fibular arches tend to form "S" patterns.^[9]
• Trisomy 18 (Edward's syndrome): 6 - 10 arches on fingertips and single transverse palmar creases in 30%.
• Trisomy 21 (Down syndrome): people with Down syndrome have a fingerprint pattern with mainly ulnar loops, and a different angle between the triradia a, t and d (the 'adt angle'). Other differences include a single transverse palmar crease ("Simian line") (in 50%), and patterns in the hypothenar and interdigital areas,^[10] lower ridge counts along digital midlines, especially in little fingers, which corresponds to finger shortening in those with Down syndrome.^[11] There is less variation in dermatoglyphic patterns between people with Down syndrome than between controls,^[12] and dermatoglyphic patterns can be used to determine correlations with congenital heart defects in individuals with Down syndrome by examining the left hand digit ridge count minus the right hand digit ridge count, and the number of ridges on the fifth digit of the left hand.^[13]
• Turner syndrome: predominance of whorls, though the pattern frequency depends on the particular chromosomal abnormality.^[14]
• Rubinstein-Taybi Syndrome: preponderance of broad thumbs, low mean ridge count, and fingerprint patterns occurring on interdigital areas.^[15]
• Schizophrenia: A-B ridge counts are generally lower than in controls.^[16]

History

The scientific study of papillary ridges of the hands and feet is credited as the beginning with the work of Jan Evangelista Purkyně in 1823.^[17]

Sir William Herschel, 2nd Baronet (1858) was the first to experiment with fingerprints in India.

Sir Francis Galton (1892) conducted extensive research on the importance of skin ridge patterns to demonstrate their permanence, but also their use for identification. In 1892, Galton published the book Fingerprints and in doing so advanced the science of fingerprint identification.

Sir Edward Henry (1893) published the book The classification and uses of fingerprints which established the modern era of fingerprint identification, which is now the basis for other classification systems.

Harold Cummins and Charles Midlo M D (1929) together with others published a widely referred book Fingerprints, Palms and soles, a bible in the field of Dermatoglyphics.

Lionel Penrose (1945), inspired by the works of Cummins and Midlo, conducted his own dermatoglyphic investigations as a further aspect of his research into Down's syndrome and other congenital medical disorders.

Schaumann and Alter (1976) published a book Dermatoglyphics in Medical disorders which summarizes the findings of dermatoglyphic patterns in disease conditions.

Seltzer, et al. (1982) conducted a study on patients with breast cancer, and concluded that the presence of six or more whorls on the fingertips of a person provided a high risk for breast cancer.

The current state of medical dermatoglyphics is that the diagnosis of illnesses can now be done with dermatoglyphic analysis alone. Currently, dermatoglyphic researchers claim a high degree of accuracy in their prognostic ability from the hand features.

References

Further reading