Medical Genetics - V. M. Zaporozhan 2005

Diagnostic methods for hereditary disorders
Dermatoglyphic method

This method is based on The Study of Skin patterns on the fingers, palms, and soles (from the Greek derma meaning skin and glyphe meaning to carve). Unlike other PARTS OF THE body, the fingers, palms, and soles feature epidermal ridges that form complex patterns. The method was introduced by F. Galton in 1892. He established that these patterns are unique to every individual and remain unchanged throughout life, prompting him to propose the method for forensic Applications.

The study of fingertip patterns is known as dactyloscopy, palm patterns as palmoscopy, and sole patterns as plantoscopy. Flexion creases are examined with the naked eye, whereas papillary lines in infants are studied using a 3x or 5x magnifying Glass.

In medical genetics, this method is primarily used as an auxiliary tool for diagnosing Chromosomal Disorders. However, because The Development of skin patterns on these body parts and the Development of the Brain occur simultaneously during the Embryonic period, the method holds significantly greater potential.

Dermatoglyphic features in chromosomal disorders

1. Single transverse palmar crease (four-finger crease).

2. Arch patterns on several fingers (Fig. 10.15).

3. Radial loops on the 1st, 4th, or 5th finger of the hand.

4. Distal axial triradius, increased atd angle.

5. Aplasia of interdigital triradiuses.

6. Transverse flexion furrow on the sole.

7. Arch pattern on the hallucal area (1st toe) of the sole.