Double NOR is not a good indicator of risk for Down syndrome.
The silver staining technique was applied to study the nucleolar organizer regions (NORs) of 38 parents of children with Down syndrome and 40 parents of healthy offspring. Double NOR (dNOR) variants were found in both groups of parents. We compared the incidence of dNOR between these two groups. Our results indicate that different conclusions can be drawn from the same data depending on how the analyses are carried out. It seems to us that dNOR is not a useful marker for predicting whether or not its carrier is at a higher risk of having children with Down syndrome.
Sheng
W W
WW
Institute of Genetics, National Yang Ming Medical College, Taipei, Taiwan.
Perng
C K
CK
Wuu
K D
KD
D002478:Cells, Cultured; D002648:Child; D004314:Down Syndrome / Q000453:epidemiology / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D009697:Nucleolus Organizer Region; D012307:Risk Factors; D012834:Silver; D013194:Staining and Labeling
D012834:Silver