We have used a half-YAC containing the human chromosome 21 long-arm telomere to clone, map, and characterize a new dinucleotide repeat polymorphism (D21S1575) close to 21qter. This marker is <120 kb from the telomeric (TTAGGG)(n) sequences and is the most distal highly polymorphic marker on chromosome 21q. This marker has a heterozygosity of 71% because of a variable (TA)(n) repeat embedded within a long interspersed element (LINE) element. Genotyping of the CEPH families and linkage analysis provided a more accurate determination of the full length of the chromosome 21 genetic map. A highly significant difference was detected between male and female recombination rates in the telomeric region: in the most telomeric 2.3 Mb of chromosome 21q, recombination was only observed in male meioses.
|Original language||English (US)|
|Number of pages||7|
|Journal||American journal of human genetics|
|State||Published - 1995|
ASJC Scopus subject areas