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PTD - 237

Test Directory - GAL 1-PUT

Synonyms

Galactose 1-phosphate uridyl transferase

Clinical Indications

GAL 1-PUT deficiency (classical galactosaemia) characteristically presents in the first week of life with failure to thrive, jaundice and hepatomegaly. The incidence in the UK is approximately 1 in 45,000. 
Untreated babies are susceptible to E.coli sepsis and galactosaemia should be considered when jaundice, hepatomegaly and sepsis occur in a neonate. The diagnosis is supported by finding of positive urinary reducing substances (Clinitest) and a negative test (providing the baby is receiving lactose-containing milk formula) is a simple and effective way of excluding classic galactosaemia. If the baby is on non-lactose formula, if the milk intake is reduced or if the baby has severe vomiting then Clinitest is not a reliable way of excluding the diagnosis and GAL-1-PUT is indicated.
If galactosaemia is suspected, the baby should be taken off lactose whilst awaiting GAL-1-PUT results.
There may be an urgent need to test for galactosaemia in a baby who has recently had a major blood transfusion. In these situations both parents may be tested. It is important that this is discussed with a Consultant Biochemist to arrange before any bloods are taken.

Request Form

Combined Pathology Blood form (Yellow/Black)

Availability

Referred test: Analysed by Genetics Laboratory, Guy's Hospital, London, if specific criteria met.

Specific Criteria

Requested by Consultant Paediatrician or agreed with Consultant Biochemist.

Turnaround Time

1 week

Specimen

Whole Blood

Volume

2 ml

Container

Paediatric orange top (lithium-heparin) tube or
 

Green top (lithium-heparin) for adults when their child has had a recent transfusion and unable to provide a sample.
Please ensure that a separate sample is collected if other Biochemistry tests are required. Recommended to only be taken Monday to Thursday to allow sufficient time to reach the referral laboratory.

Causes for Rejection

Not meeting specific criteria.

Interpretation

A high haemoglobin level may interfere with the test and cause false positive results. A false negative result may occur of the baby has recently had a blood transfusion and the test is not valid within 6 weeks of a major transfusion.

Lab. Handling

Processing: DO NOT SEPARATE SAMPLE. Store as whole blood at 4C in separating fridge (CB39).
Referral: GAL1P and send as soon as possible to the referral laboratory.


Version 1.0 / June 2014                                                                                                          Approved by: Consultant Biochemist