A family study of dermatoglyphic traits in India: Segregation analysis of accessory palmar triradii and the atd angle

S. B. Gilligan, I. B. Borecki, S. Mathew, M. Vijaykumar, K. C. Malhotra, D. C. Rao

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


Accessory triradii and the atd angle were examined via complex segregation analysis in order to evaluate possible genetic effects on these dermatoglyphic traits, measured in an endogamous Brahmin caste of peninsular India. The phenotypes considered included: presence of accessory palmar triradii a′ and d′, associated with the interdigital areas II and IV, respectively; presence of an accessory axial triradius tt′ associated with the proximal margin of the palm; and an arctanh‐transformation of the atd angle measurement. For all accessory triradii considered in the present investigation familial resemblance was evident. The most parsimonious model which could account for the observed resemblance was a multifactorial model that includes polygenic effects as well as transmissible environmental effects that are inherited in the same pattern as polygenes. Evidence of familial resemblance was also found for the arctanh‐transformed atd angle, which could be attributed, initially, to both a major effect and a multifactorial component. Tests of transmission of a putative major gene were performed which yielded results consistent with Mendelian transmission, although an alternative test of no transmission of the major effect also fit the data. In light of these contrasting results we are precluded from accepting with confidence the notion of a major gene influence on the atd angle. We have concluded that the accessory triradii a′, d′, and tt′, and the atd angle are influenced by multifactorial effects, including additive polygenes and possible environmental factors, such as intrauterine effects.

Original languageEnglish
Pages (from-to)117-123
Number of pages7
JournalAmerican Journal of Physical Anthropology
Issue number1
StatePublished - Sep 1987


  • Accessory palmar triradii
  • Dermatoglyphics
  • Segregation analysis
  • atd angle


Dive into the research topics of 'A family study of dermatoglyphic traits in India: Segregation analysis of accessory palmar triradii and the atd angle'. Together they form a unique fingerprint.

Cite this