Galactokinase
Label Mnemonic: GALKINASE
Epic Lab Code: LAB3189
Downtime Form: A-1a Miscellaneous Request
Commercial Mail-out Laboratory
5231 RCP
356-8593
Specimen(s):
Blood
Specimen Instructions:
Collection date is required on request form for processing; include type of specimen sent (heparinized whole blood) on request form.
Collection Medium:
Lavender top tube 3 mL (EDTA)
Minimum:
Minimum: Full draw; 3.0 mL whole blood from fasting patient in lavender top (EDTA) tube
Peds Minimum: 2 mL whole blood from fasting patient in lavender top (EDTA) tube
Rejection Criteria:
Sample must be received at reference laboratory within 48 hours of collection, collect Monday through Thursday only; do not collect on Fridays, holidays, day before a holiday, or weekends. Specimen cannot be frozen.
Delivery Instructions:
Submit specimen to laboratory as soon as possible after collection.
Testing Schedule:
Monday - Thursday only, no weekends or holidays.
Turn Around Time:
9 days upon receipt at reference laboratory
Reference Range:
> or = 0.7 nmol/h/mg of hemoglobin
Interpretive Data:
Low values suggest galactokinase deficiency.

Only results below the normal range are clinically significant. Elevated values have no clinical significance.
Comments:
Whole blood to be washed at reference laboratory. If specimen cannot arrive within 48 hours, please send washed erythrocytes. Draw blood in a lavender top (EDTA) tube from a fasting patient (4 hour preferred, nonfasting acceptable), and send 3 mL of whole blood refrigerated.

Cautions:
It is important to notify the laboratory if the patient has been transfused prior to specimen collection. The results of testing performed in erythrocytes are invalid following a transfusion, including analysis of enzymes, biochemical phenotyping, or galactose-1- phosphate.

The most common cause of galactosemia is GALT deficiency. In most cases, GALT deficiency should be ruled out prior to evaluating for GALK deficiency.

Useful For:
Diagnosis of galactokinase deficiency, the second most common cause of galactosemia.
Methodology:
Radioisotopic
CPT Code:
82759