Dermatoglyphics

Dermatoglyphics (from ancient Greek derma = "skin", glyph = "carving") is the scientific study of fingerprints and can be traced back to 1892 when one of the most original biologists of his time Sir Francis Galton, a cousin of Charles Darwin, published his now classic work on fingerprints. The study was later termed Dermatoglyphics by Dr. Harold Cummins, the father of American fingerprint analysis, even though the process of fingerprint identification had already been in use for several hundred years. All primates have ridged skin. It can also be found on the paws of certain mammals, and on the tails of some monkey species. In humans and animals, dermatoglyphs are present on fingers, palms, toes and soles. This helps shed light on a critical period of embryogenesis, between four weeks and five months, when the architecture of the major organ systems is developing.

The word dermatoglyphics comes from two Greek words (derma, skin and glyphe, carve) and refers to the friction ridge formations which appear on the palms of the hands and soles of the feet. Characteristically, hair does not grow from this area. The ridging formations serve well to enhance contact, an area of multiple nerve endings (Dermal Papillae) and aids in the prevention of slippage. People of African ancestry display reduced skin pigmentation in the designated locations. All studies of the dermal ridge arrangements including genetics, anthropology and Egyptology are classified under the term dermatoglyphics.

The word subdermatoglyphic is cited as one of the longest isograms in the English language.

Genetic disorders
Unusual dermatoglyphic patterns often relate to genetic disorders. One study of fetuses with chromosomal abnormalities showed that the dermatoglyphic patterns were delayed by more than two weeks.


 * Trisomy 21 (Down syndrome): People with Down syndrome have a finger print pattern with mainly ulnar loops, and a significantly different angle between the triradia a, t and d (the 'adt angle'). Other differences often include a single transverse palmar crease ("Simian line") (in 50%), and patterns in the hypothenar and interdigital areas, lower ridge counts along digital midlines, especially in little fingers, which corresponds to finger shortening in those with Down's syndrome. There is less variation in dermatoglyphic patterns between people with Down syndrome than between controls, 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.
 * Turner syndrome: Predominance of whorls, although the pattern frequency depends on the particular chromosomal abnormality.
 * 47, XXY (Klinefelter's 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.
 * Trisomy 13 (Patau syndrome): Excess of arches on fingertips and single transverse palmar creases in 60%.
 * Trisomy 18 (Edward's syndrome) 6 - 10 arches on fingertips and single transverse palmar creases in 30%.
 * Inborn blindness: Initial data points to abnormal triradius and excess of arches on fingertips
 * Cri du chat (5p-): Excess of arches on fingertips and single transverse palmar creases in 90%.
 * 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. Increased incidence of single transverse palmar creases.
 * Astigmatism relation:
 * Naegeli–Franceschetti–Jadassohn syndrome