Metabolic Disorders: The Blue-Red Test for Trouble

METABOLIC DISORDERS

If a baby seems normal at birth but soon appears listless, fails to gain weight, and suffers from jaundice, vomiting and diarrhea, his mother can hardly be expected to know that he may lack the enzyme galactose1 -phosphate uridyl transferase. Neither can doctors, unless they send samples of the baby’s blood and urine for timeconsuming, costly lab tests. Then, if the tests show an excess of galactose (milk sugar) in the blood or urine, doctors know what the trouble is and how to remedy it.

Since the baby cannot metabolize galactose to glucose, the sugar that the body burns for energy, he must be put on a special milk-free diet. Otherwise he is almost certain to develop cataracts and cirrhosis of the liver and, if he does not die, to be mentally retarded.

Last week a California researcher described a cheap test that will quickly show whether a baby has galactosemia.

At the City of Hope Medical Center in Duarte, Dr. Ernest Beutler has concocted a reagent solution into which he puts a single drop of blood. The solution (which contains methylene blue) is blue. Blood from normal, healthy subjects turns it red within half an hour. But one of the 24 apparently healthy subjects whose blood Dr. Beut ler tested turned out to be abnormal: she was apparently a carrier of the recessive gene for galactosemia, for her blood took an hour to turn the solution red. A drop of blood from a galactosemic baby, who has inherited a double dose of the defective genes, one from each parent, will not turn the reagent red even if blood and reagent are incubated together for hours.

Galactosemia is generally believed to be rare, and it probably is. But no one has been certain, because the tests have been so difficult. With Dr. Beutler’s cheaper and simpler method many more cases of galactosemia will be found.

Given a special diet, children with the disorder can develop normally.