The scientific study of fingerprints, the word dermatoglyphics comes from ancient Greek (derma: "skin" and glyph: "carving"), a term devised by Harold Cummins considered by most to be the father of scientific fingerprint analysis.
The science of dermatoglyphic analysis is a well-documented and standardized biometric that has widespread, if largely unnoticed, clinical significance.
All primates have ridged skin, and it can also be found on the paws of certain mammals and on the tails of some monkey species. In humans, dermatoglyphs are present on fingers, palms, toes, and soles, and give insight into a critical period of embryogenesis, between 4 weeks and 5 months, when the architecture of the major organ systems is developing. Unusual dermatoglyphic patterns often relate to genetic disorders:
- Trisomy 21 (Down syndrome): Usually all are ulnar loops, Simian Creases in 50%.
- Turner syndrome: Predominance of whorls
- 47 XXY (Klinefelter's syndrome): Excess of arches
- Trisomy 13 (Patau syndrome): Excess of arches and Simian creases in 60%
- Trisomy 18 (Edward's syndrome) 6 - 10 arches and Simian creases in 30%
- Cri du chat (5p-): Excess of arches and Simian creases in 90%
Dermal ridge differentiation takes place early in fetal development. The resulting ridge configurations are genetically determined and influenced (or modified) by environmental forces. Ridge formation is influenced by discrete elevations of the skin on the fingertips, called volar pads, which first appear in human embryos at about six and a half weeks. As the volar pads shrink, it places stress on the skin layers. The fingerprint pattern ridges then form perpendicular to this stress.