DERMATOGLYPHICS: An introduction to the dermatoglyphs of the human hand.

Dermatoglyphics – a moment of science!

The word ‘dermatoglyphics‘ was first coined by Harold Cummins in 1926, and refers to the study of the characteristics in the skin ridges of the hands and the feet. What are the most common dermatoglyphic characteristics?

FINGERPRINTS:

In most populations around the world is the ‘ulnar loop’ the most observed fingerprint pattern (see: the fingerprint of the pinky finger in the picture above). Loops are most frequently found on the little finger (and middle finger); loops are least frequently found on the pointer finger.
In some Asian populations the ‘whorl’ (see: the fingerprint of the ring finger in the picture above) is more common than the ‘ulnar loop’. Whorls are more often seen on the thumb and ring finger.
In population research usually the pointer finger demonstrates more variation than the the other fingers. For example the most common ‘ulnar loop’ is least often seen on the pointer finger, which often exhibits an other pattern such as: the ‘arch’, ‘tented arch’, ‘whorl’ or ‘radial loop’ (see: the pointer finger in the picture above).

PALMAR DERMATOGLYPHICS:

The variations in the dermatoglyphics of the handpalm are much more complex than the variations in the fingerprints. An important element concerns the presence of the ‘palmar triradii’ (see: a, b, c, d, and t in the picture above): normally each finger is featured with a palmar triradius – triradius t belongs to the thumb (the thumb mouse – a.k.a. as the ‘thenar’, or in palmistry: ‘mount of Venus’ could be recognized as the third phalange of the thumb).
However, the number of palmar triradii varies with the presence of palmar ‘loops’ (or: palmar ‘whorls’). Usually the link between the number of fingers (D = digits), palmar triradii (T) and palmar loops (L) can be described with the following formula, which is known as the Penrose topological formula (Lionel Penrose, 1965):

T = L + D – 1

More details available via:
The history of research in fingerprints & dermatoglyphics – a review!

Picture: example of a normal pattern of dermatoglypics [NOTICE: If the ‘c-line’ is ending between the ring- and middle finger it always creates a palmar ‘loop’, which implicates that the author of the picture has missed 6th palmar triradius between/below the c and d triradius]

Palmar dermatoglyphics.

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27 Characteristics of the hand in Down syndrome (trisomy 21).

Phantom picture of the hand in Down syndrome!

In 1963 L.S. Penrose presented the first ‘phantom picture’ describing the typical hand characteristics in Down syndrome. More detailed ‘phantom pictures’ were presented by Schaumann & Alter (1976), Rodewald (1981). This month (2010) a more detailed updated version of the visualisation became available – featuring 27 characteristics of the hand in Down’s syndrome!

What are the most common hand characteristics in Down syndrome?

HAND LINES:
A common characteristic is the presence of the famous ‘simian line‘; an alternative is the presence of a Sydney line.

DERMATOGLYPHICS:
Here one should especially notice the hypothenar zone of the hand (in palmistry a.k.a. ‘mount of moon’); usually this zone a large ‘ulnar loop’ pattern combined with a high positioned palmar axial triradius.

HAND SHAPE:
Short fingers (thumb and pinky finger are often abnormally short) + a square shaped palm.

NOTICE: The author of the new ‘phantom picture’ for Down syndrome described a specific guideline which states that in all cases of Down syndrome certain combinations of the 27 characteristics are found in both the fingers AND the palm of the hand!

More details available at:
How to use the famous ‘single palmar crease’ (a.k.a. simian line) as a marker in hand diagnostics!

Photo: example of a baby hand in Down syndrome

Example of a baby hand in Down syndrome (trisomy 21).