Sex differences and bilateral asymmetry in dermatoglyphic pattern elements on the fingertips

Area of Science:

• Human genetics
• Anthropometry
• Forensic science

Background:

• Dermatoglyphics, the study of fingerprint patterns, offers insights into human development and genetics.
• Bilateral asymmetry in physical traits can reflect developmental stability and genetic factors.
• Ulnar and radial loops are common fingerprint patterns analyzed for population and genetic studies.

Purpose of the Study:

• To investigate the genetic control of dermatoglyphic pattern asymmetry on fingertips.
• To determine if fingertip patterns (ulnar and radial loops) exhibit bilateral asymmetry.
• To assess the heritability of this asymmetry and compare it between sexes.

Main Methods:

• Analysis of dermatoglyphic patterns (ulnar and radial loops) from 999 individuals (515 males, 484 females) across 539 Polish families.
• Measurement of bimanual difference (right hand minus left hand) as an indicator of asymmetry.
• Statistical analysis of asymmetry, including variance and correlation between relatives.

Main Results:

• Significant asymmetry was observed between right and left hand fingertips for ulnar and radial loops across digits and sexes.
• Sex differences in asymmetry were found to be small.
• The mean and variance of asymmetry did not significantly differ between males and females.
• Correlations between relatives indicated a low hereditary component for dermatoglyphic asymmetry.

Conclusions:

• Fingertip dermatoglyphic patterns (ulnar and radial loops) are inherited.
• The asymmetry of these patterns has a minimal hereditary component.
• While patterns are inherited, the variation in asymmetry between hands is not strongly genetically determined.