Investigators at Children's Hospital Medical Center, Boston, have devised a new test for cystic fibrosis, based upon an analysis of the sodium and potassium concentration in finger and toe nails.
"Some might question the need for a new test for cystic fibrosis since the standard sweat test is one of the most reliable in medicine," Harry Shwachman, MD, told The Journal. "There is, however, need for a rapid screening procedure which can be applied to the newborn and for a test to detect the heterozygote or carrier of the CF gene.
A second test would also be helpful in confirming a diagnosis in patients with an equivocal sweat test.
The test devised by Shwachman and Louis Kopito, MS, a physicist at Children's Hospital, cannot in its present form be used for mass screening. "It is too difficult a procedure at present for use as a screening method," Shwachman said. "It