Carbohydrate Disorders
Galactosaemia screen
Patients with unexplained or prolonged jaundice should be screened for classical galactosaemia. The condition is often accompanied by septicaemia, has an incidence of around 1 in 45,000 births and is exacerbated by lactose containing milk. Reducing substances are not always found in urine and therefore a Beutler screening test should be carried out. Approx. 0.2 – 0.5ml heparinised blood should be sent directly to the laboratory. Note: the test is not valid if the patient has undergone a recent blood transfusion (within 4 months) and the test could also give a false positive result with G-6-PD deficiency. Transfused patients would require Gal-1-P analysis on whole heparinised blood (5ml). Since these samples require immediate processing it is important to warn the lab of any Gal-1-P analyses.
| Test | Required specimen & volume | Special precautions | Turnaround time | Reference ranges | Section |
|---|---|---|---|---|---|
| Sugar Chromatography | 5ml plain U | None | 3 working weeks | Qualitative | Metabolites |
|
α-glucosidase
Pompe (GSDII) |
5ml EDTA | Must reach laboratory within 48 hours of venepuncture | 2 working weeks |
3 – 20 µmol/g/h – acarbose 2 – 15 µmol/g/h + acarbose |
Lysosomal |
|
Cross Reactive Immunologic Material (CRIM) Analysis for Pompe disease |
Contact laboratory for information | Contact laboratory | 3 working days | Qualitative | Lysosomal |
|
Beutler Test
Galactosaemia |
0.5 ml HEP | Must reach laboratory within 24 hours of venepuncture | 3 working days | Qualitative | Metabolites |
|
Galactose-1-phosphate
Galactosaemia monitoring |
5ml HEP | Must reach laboratory within 24 hours of venepuncture | 3 working weeks | 5 – 10 µg/ml packed red cells | Metabolites |