A clinical study of the diagnosis of cystic fibrosis by instrumental neutron activation analysis of sodium in nail clippings.

This article reports on the possibility of using instrumental neutron activation analysis 
(INAA) of sodium in nail clippings for diagnosing cystic fibrosis (CF) 
in children and adults, for detecting heterozygotes and for screening in 
the neonatal period. Nail clippings from 1322 newborns, 22 CF patients 
(two of them newborns), 52 healthy controls and 22 heterozygotes were 
analyzed. The discrimination between CF patients and controls was found to 
be precise for individuals above one year of age and INAA 
of nail clippings should be accepted as a diagnostic test for 
CF after this age. Heterozygotes could not be detected by the 
method. During the first five days of life there is a 
big overlap between the values from normal newborns and those of 
CF children, which makes the method invaluable for early screening for 
CF. 