The enzyme galactose-1-phosphate uridyltransferase (GALT) is needed in the use of galactose-1-phosphate so that it does not accumulate in the body. A very rare genetic disorder resulting from an inborn (inherited or acquired during intrauterine development) error of galactose metabolism may occur, known as galactosemia.
Galactokinase (GALK) measurement is used to identify GALK deficiency, a rare autosomal recessive disorder that causes galactose defects, which can result in cataracts if not identified early. GALK deficiency is one type of galactosemia. The screening test should be done immediately to enable diet treatment if testing is positive.
Obtain a 5-mL venous blood sample.
Anticoagulate with heparin.
Observe standard precautions. Label the specimen with the patient’s name, date and time of collection, and test(s) ordered. Place the specimen in a biohazard bag.
Decreased values are associated with galactosemia, a rare genetic disorder transmitted in an autosomal recessive fashion. The resulting accumulation of galactitol or galactose-1-phosphate can result in juvenile cataracts, liver failure, failure to thrive, and intellectual disability.
Pretest Patient Care
Explain test purpose and procedure. Genetic counseling may be necessary.
Follow guidelines in Chapter 1 for safe, effective, informed pretest care.
Posttest Patient Care
Review test results; report and record findings. Modify the nursing care plan as needed. See newborn screening in Chapter 11.
Instruct parents of infants and children with positive test results that the disease can be effectively treated by removing galactose-containing foods, especially milk, from the diet. With dietary galactose restriction, liver and lens changes are reversible.
Follow guidelines in Chapter 1 for safe, effective, informed posttest care.