Human chromosomal heteromorphisms in American blacks. VI. Higher incidence of longer Y owing to non-fluorescent (nf) segment

J Med Genet. 1982 Aug;19(4):297-301. doi: 10.1136/jmg.19.4.297.

Abstract

Sixty normal male American blacks were selected to study the length of fluorescent (f), non-fluorescent (nf), and total length of the Y chromosome by the QFQ technique. The length of the Y chromosome was classified into five groups: very small, small, average, large, and very large. The frequencies of Y/F indices for these groups were 0.0, 3.33, 56.67, 30.00, and 10.00%, respectively. The variation in the total length of the Y chromosome was accounted for by variations in the length of the nf as well as the f segment. A longer Y was noted in blacks owing to an increase in size of the nf segment in comparison with a normal Caucasian population. Forty percent of American blacks had large or very large Y chromosomes, while this class comprised only 18.3% of Caucasians, which is significantly different (p less than 0.05). Furthermore, the length of the Y chromosome was normally distributed among Caucasians, while among blacks the distribution was skewed to the left. The mean Y/F, f/F, and nf/F indices were 1.09 +/- 0.10, 0.42 +/- 0.09, and 0.67 +/- 0.04, respectively.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Black People*
  • Black or African American
  • Humans
  • Male
  • Microscopy, Fluorescence
  • Sex Chromosome Aberrations / epidemiology*
  • Sex Chromosomes*
  • United States
  • Y Chromosome*