Galactosaemia
Classical Galactosaemia is also an autosomal recessive condition caused by a deficiency of an enzyme galactose-1-phosphate uridyl transferase. This enzyme is important for the breakdown of galactose, one of the two sugars that make up lactose in human and cow’s milk. Approximately one in every 19,000 infants born in Ireland may have this condition. However, it is particularly common among infants born to Traveller parents in whom the incidence is approximately 1 in 450 births. Consequently in the non-traveller Irish community the incidence occurs in about one in every 36,000 births.
If not detected and treated during infancy, the disorder may cause damage to the liver and may occasionally be life threatening. As a result of the condition, galactose and galactose-1-phosphate accumulate in blood; galactose-1-phosphate is toxic. The infant may present with jaundice; there may be a bleeding disorder with a tendency to bleed spontaneously; this may cause a brain haemorrhage. The affected baby may also develop an E coli septicaemia; the infants may develop cataracts. Early detection and treatment with a galactose-free diet will prevent the early clinical symptoms of the disorder; some of the longer term complications, such a dyspraxia, ataxia or reduced fertility in later life may still despite treatment.
Because the condition is relatively common in infants born to Traveller parents, a special screening test, the Beutler test, is offered to all infants born to Traveller parents and to siblings of known cases at birth (Day 1 of life). They should be offered a galactose free feed (Soya-based) and should not breast feed until the result of the test is available. This protects the infant should he/she have the condition. For those mother’s wishing to breast feed, they should discuss this with their midwife – they can express their milk until the result of the test is available. The test is performed every morning (Monday to Saturday); the results should be available within six hour of the laboratory receiving the sample.
Clinicians should never depend solely upon the general population screening for the diagnosis of Classical Galactosaemia, but should still consider this condition in any baby who presents early conjugated hyperbilirubinaenia and other symptoms e.g. vomiting or floppiness.
Action following detection of raised result
If the bloodspot total Galactose is raised and the Beutler RAP is reduced then Classical Galactosaemia is suspected; the following clinical procedure is implemented:
1. The Clinical Liaison Officer (NNBSL) will:
- contact the Maternity Unit in which the baby was born. Clear instructions are given to the Maternity Unit staff include the baby’s demographic details, the condition suspected and the arrangements for further examination and investigations locally.
- Inform the Registrar or Consultant Metabolic Paediatrician on duty of the possibility of a new case of Galactosaemia
2. On admission to the local paediatric unit, the baby should be examined clinically and blood taken for plasma bilirubin and LFTs and coagulation screen
3. if the blood tests are abnormal, particularly the coagulation screen, the infant should be managed as a case of Classical Galactosaemia until the results of the enzymes (Galactose-1-Phosphate Uridyl Transferase (Gal-1-PUT) are available
4. The clinician should be advised to contact the On-call Consultant Metabolic Paediatrician, to start the infant on a Soya-based feed, draw blood for blood cultures and correct the coagulopathy.
5. Send another Newborn Screening Card by Courier to the NNBSL for repeat Beutler test
6. 2mL of lithium heparin blood should be sent to the Reference laboratory in Bristol for Gal-1-PUT, stating that the sample MUST arrive within 24 hours of collection and should be sent on a Monday to Thursday ONLY. The laboratory should be contacted in advance so as to expect the sample
Once the results of the Gal-1-PUT are known, then the screening process is complete
