Family studies on nucleoside phosphorylase and the short arm of chromosome 14.

A family with two nucleoside phosphorylase-deficient patients has been scored for the segregation of NP0 and the variable region 14p. The mose likely 14p:NP recombination fraction is 0.15 in males and 0.30 in females. There is no family data to assign the Pi:Gm linkage group to chromosome 14, but as immunoglobulin heavy chain has been assigned to this chromosome by somatic cell methods the most likely gene order is 14p:NP:Pi:Gm with Pi in 14q2 and Gm in 14(q23 leads to q32), but the order 14p:NP:Gm:Pi with Pi in 14(q24 leads to qter) and Gm in 14(q22 leads to q24) is not excluded. The available linkage data between biochemical markers on acrocentric chromosomes and their short arm markers suggest that there may be more recombination towards the ends of human chromosomes whether or not those ends carry centromeres.