Lawrence S, Keats B J, Morton N E
Department of Child Health, University of Southampton, Princess Anne Hospital, UK.
Ann Hum Genet. 1992 Oct;56(4):295-301. doi: 10.1111/j.1469-1809.1992.tb01156.x.
The AD1 locus on chromosome 21 (MIM 104300) maps to the beta-amyloid precursor locus (APP) at approximately 27.7 Mb from pter (10.9 cM in males and 33.9 cM in females), flanked proximally by D21S8 and distally by D21S111, with D21S124 and D21S210 close but of uncertain order. AD1 accounts for 63 +/- 11% of multiplex Alzheimer pedigrees for which lod scores have been reported. Since a much smaller proportion of pedigrees have mutations in the cDNA for beta-amyloid (APP exons 16 and 17), it is likely that the AD1 locus spans controlling elements near those exons. There is no evidence for a second locus on chromosome 21. The remaining pedigrees may include sporadic cases as well as mutations at an AD2 locus on another chromosome.
位于21号染色体上的AD1位点（MIM 104300）定位于β-淀粉样前体蛋白位点（APP），距离染色体短臂末端约27.7 Mb（男性为10.9 cM，女性为33.9 cM），近端侧翼为D21S8，远端侧翼为D21S111，D21S124和D21S210距离较近但顺序不确定。已报告连锁对数的多重阿尔茨海默病家系中，63±11%可归因于AD1。由于β-淀粉样蛋白cDNA（APP外显子16和17）发生突变的家系比例要小得多，因此AD1位点可能跨越了这些外显子附近的调控元件。没有证据表明21号染色体上存在第二个位点。其余家系可能包括散发病例以及另一条染色体上AD2位点的突变。
