Expression of folate-sensitive fragile sites in lymphocyte chromosomes.
The expression of folate-sensitive fragile sites (FS) was analyzed using MTX as a fragility inducer in seven normal subjects [four unrelated persons and three members of one family (father, mother, and son)]; a woman heterozygous for fra Xq27.3 with a 47,XXX karyotype; and her son, affected by the fra-X syndrome. The mean expression of chromosome lesions (CL) other than Xq27.3 was 70.1% (686CL in 978 metaphases), and the coincidence between CL and FS was 68.9%. We propose six new c-fra sites: bands 4q33 and 11q22 because they were found in two members of the same family; band 13q32 because it had a frequency of expression of 3% of metaphases; and bands 3p13, 8q21, and Xq21 because they were observed in four of the nine individuals studied.
Fuster
C
C
Departament de Biologia Cel.lular i Fisiologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Miró
R
R
Templado
C
C
Barrios
L
L
Egozcue
J
J
D000328:Adult; D002478:Cells, Cultured; D002871:Chromosome Banding; D043283:Chromosome Fragile Sites; D002873:Chromosome Fragility; D005260:Female; D005492:Folic Acid / Q000494:pharmacology*; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000648:ultrastructure; D008297:Male; D008727:Methotrexate / Q000494:pharmacology; D014960:X Chromosome
D005492:Folic Acid; D008727:Methotrexate