Family study of common fragile sites.
The frequency of folate-sensitive common fragile sites (1p31, 1q44, 3p14, 3q26.2, 6q26, 16q23, Xp22.3) was determined in 19 healthy individuals from four families. The individuals consisted of 12 males and 7 females from 1 to 59 years of age. The frequency showed intrafamilial variation, but we were unable to demonstrate that the frequency was inherited in a Mendelian codominant fashion. In eight subjects whose chromosome 3 homologues could be distinguished by Q-band polymorphism, breakages at 3p14 occurred with equal frequencies on the homologues. Our study suggests that common fragile sites are a part of normal chromosome structure, and the frequency of their expression largely depends on environmental factors.
Sugio
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Y
Division of Medical Genetics, Kanagawa Children's Medical Center, Yokohama, Japan.
Kuroki
Y
Y
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D043283:Chromosome Fragile Sites; D002873:Chromosome Fragility; D002893:Chromosomes, Human, Pair 3 / Q000648:ultrastructure; D005260:Female; D005823:Genetics; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged