Galactokinase, Blood

Casandra

Casandra Test Code MC40871Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID GALKCPT Code 82759

Clinical Use

Use

This test is useful for the diagnosis of galactokinase deficiency, a very rare autosomal recessive disorder affecting the first step of galactose metabolism. It helps evaluate children with unexplained bilateral congenital or juvenile onset cataracts, which is a major clinical manifestation of this deficiency. The disorder has a higher frequency in the Romani population, and a prevalence estimated to be between 1 in 50,000 to 1 in 100,000 live births. Early detection and treatment with a galactose-restricted diet may prevent or reverse cataract formation.

Special Instructions

This test is not suitable for monitoring dietary compliance; for this purpose, the GAL1P / Galactose-1-Phosphate, Erythrocytes test should be used. It is recommended but not required to complete the Biochemical Genetics Patient Information form to assist in test result interpretation. Informed consent for genetic testing is required for New York clients. If not ordered electronically, a Biochemical Genetics Test Request form should accompany the specimen.

Limitations

This assay cannot detect deficiencies in galactose-1-phosphate uridyltransferase (GALT), uridine diphosphate-galactose 4' epimerase (GALE), or galactose mutarotase (GALM). Improper specimen collection and handling, post-transfusion samples, or inappropriate test selection can lead to diagnostic confusion. The test results are invalid after a transfusion due to potential interference with readings.

Test Details

New York Approved