The inheritance of digital dermatoglyphic patterns in 54 American Caucasian families

We searched for single gene effects in determining digital patterns and compared with the evidence for monogenic determination in Israelis (Slatis et al., '76). Our subjects were 108 parents from central Louisiana and 123 of their offspring; there were 127 females and 104 males ranging in age from eight to 66 years. Arches on the thumb--Among 11 subjects, two were bilateral, and three pairs were related, two as parent-child and one as sib-sib; the findings support the concept of an incompletely penetrant dominant gene. Radial loops on the thumb--three occurred unilaterally in unrelated subjects. Ulnar loops (U) and whorls (W) on the thumb--Phenotype frequency was 104 UU, 65 UW, 47 WW, 15 other. The proportion of UU offspring was highest with both UU parents and diminished as the parents had increasingly more W, supporting the single locus hypothesis. Arches (A) on the fingers--71 A, 160 non-A showed a greater A frequency than in the Israelis. The proportion of A offspring was highest with both A parents and diminished as the parents became non-A. Sequence WWUWW--Among nine subjects, one was bilateral, two left, and six right; two pairs related as parent-child and sib-sib. Sequence WUUWW--Among five subjects, one was bilateral, and three were related as parent-offspring. Radial loops on index fingers--Frequency of 32% was greater than in the Israelis. Middle fingers--86% were U, 73% being bilateral. Radial loops on ring and little fingers--Among eight unilateral subjects, none was related. Ulnar loops and whorls on ring fingers--Proportion of UU offspring was greatest with both UU parents and diminished as parents became WW. We conclude that the Louisianians showed evidence for single gene effects similar to that of the Israelis.