It’s 11 am on Easter Monday in Dublin. Emily is a 6-day-old baby girl, born at 37 weeks via normal vaginal delivery across the Irish Sea in Wales while her mother was visiting some friends.
When Emily was 3 days old, her mother returned to Ireland to stay with her own mother for some early baby support. Since day two of life, Emily has been vomiting after feeding. She is bottle-fed, and since yesterday, she has only been accepting half of each bottle. Her mother initially thought she was tired from the long trip but brought her to the ED this morning because she had been quiet, hadn’t been crying as usual with nappy changes and seemed too sleepy to take this morning’s bottle.
Emily was born in good condition by spontaneous vaginal delivery at 37/40. Her birth weight was 2.9kg. She was jaundiced on the second day of life but below phototherapy levels.
Social history: Emily’s parents are both healthy and from the Irish Traveller Community.
Emily’s current weight is 2.45kg (a 16% drop from her birth weight). She’s jaundiced and lethargic, her anterior fontanelle is sunken, and she looks dehydrated. You can palpate the liver 2 cm below the right costal margin. The spleen is not palpable. Otherwise, there are no positive findings. She’s afebrile with normal observations.
This baby has some red flags that will make anyone concerned. She is vomiting, lethargic, jaundiced, dehydrated, has hepatomegaly and has lost 16% of her birth weight. Emily is definitely sick. The list of potential diagnoses is extensive, but sepsis should always be at the top of your list.
As you’re taking bloods for an FBC, U&E, LFT, ammonia and blood culture, you’re told that Emily is hypoglycaemic so you collect additional bloods for a hypoglycaemia screen.
First, let’s correct the glucose!
Follow your local guidelines regarding the initial investigation and management of hypoglycaemia and give 10% Dextrose 2mL/kg IV as soon as possible.
Bloods should be collected prior to treatment, but do not delay treatment due to problems collecting samples.
As this could be a metabolic presentation, instigate a generic management approach:
- Clinical stabilisation
- Antibiotics
- Stop feeds
- Give maintenance fluids with electrolytes to maintain hydration
The hypoglycaemia screen
The hypoglycemia workup should preferably be collected while the patient is hypoglycaemic before giving glucose.
The basic screen aims to identify the most common endocrine or metabolic conditions responsible for hypoglycemia. Briefly, it involves glucose, ketones (Beta-hydroxybutyrate), insulin, cortisol, Growth Hormone (GH), ammonia, lactate, free fat acids, serum amino acids, acylcarnitines profile (Guthrie card) and urine for organic acids and ketones.
Discussing them in depth is beyond the scope of this post, but if you want to learn more, you can refer to this post by PaediatricFOAMed.
Find out if your institution has a “hypoglycaemia kit” ready to go, as hypoglycaemia in a neonate can be a stressful situation that requires quick action.
Emily’s blood sugar normalises. She has a full septic screen and is started on intravenous broad-spectrum antibiotics. But what’s her diagnosis?
Emily is hypoglycaemic with raised ketones, a normal response we would expect as she’s using fat as an alternative source of energy. However, in addition to this, Emily has hepatomegaly and raised liver enzymes, which, together with hypoglycaemia, point towards a diagnosis of galactosaemia.
The worldwide incidence of classic galactosaemia is around 1:45,000 live births. Some countries screen for galactosaemia in their newborn screening programmes (Ireland, UK, New Zealand and some parts of Australia). Because of its autosomal recessive inheritance, galactosaemia is more common in some ethnic groups.
In Ireland, around 1 in every 16,200 babies born each year may have galactosemia, however in the Irish Traveller community, this incidence is approximately 1 in 450 births, compared to only 1 in 36,000 in the non-traveller Irish population. Because of the high incidence of babies born to parents from the travelling community, these babies are specifically screened earlier, on day 1 of life, in Irish maternity hospitals.
High-risk babies’ diets should exclude galactose, so newborn babies of Irish travelling families are given soy-based formula rather than breast milk or standard formula until their screening test result is known.
A bit about galactosemia
As per the definition, “galactosaemia” refers to disorders of galactose metabolism that include classic galactosaemia, clinical variant galactosaemia, and biochemical variant galactosaemia (Gene Reviews). The most common is classic galactosemia, an autosomal recessive disorder caused by a defect in the enzyme galactose-1-phosphate uridyl transferase (GALT), which is important in the transformation of galactose into energy.
Galactosaemia occurs after the affected patient receives the sugar galactose, which is present in milk. Accumulation of galactose-1-phosphate results in damage to the brain, liver, and kidney. The diagnosis is made by measuring the (GALT) enzyme activity (which will be low), detecting an elevated concentration of galactose-1-phosphate in erythrocytes (the substrate), or testing for pathogenic mutations (two copies) in the GALT gene. The presence of a reducing substance in a routine urine specimen may be the first diagnostic clue.
Liver failure is a predominant finding in galactosemia. Besides that, the affected neonate presents with vomiting, hypoglycaemia due to an inability to metabolise glucose, feeding difficulty, seizures, irritability, jaundice, hepatomegaly, splenomegaly, cataracts and Escherichia coli sepsis.
Treatment of the newborn requires the exclusion of all lactose sources from the diet and the use of lactose-free formulas. This must be started immediately after the disorder is suspected clinically while awaiting screening results in high-risk groups or following positive newborn screening results.
Interestingly, suppose the galactose-free diet is started early enough. In that case, the symptoms will disappear, jaundice will resolve within days, liver and kidney functions will return to normal, liver cirrhosis may be prevented, and cataracts may clear.
Later in life…
Even patients treated from the very first few days of life can develop complications as they grow up. Galactosaemia represents a spectrum with symptoms varying from mild growth retardation, delayed speech development, verbal dyspraxia, difficulties in spatial orientation and visual perception, and mild intellectual deficit. Neuropsychological problems can appear during adolescence.
Unfortunately, ovarian dysfunction is an almost inevitable consequence that can’t be prevented even by a strict diet. It is often seen early in infancy or childhood with hypergonadotropism.
References
Berry JT. Classic Galactosemia and Clinical Variant Galactosemia In: Adam , HH. Ardinger, RA. Pagon, S. E. Wallis, L. J. H. Bean, K. Stephens, & A. Amemiya (Eds.), GeneReviews® [online book].
Berry, JT, Walter JH, Fridovich-Keil JL. Disorders of Galactose Metabolism. In: Saudubray J-M, Baumgartner MR, Walter JH. (editors) Inborn Metabolic Diseases. Diagnosis and treatment. 6th Edition. Springer 2016.
HSE. A Practical Guide to Newborn Bloodspot Screening In Ireland. December 2018. https://www.hse.ie/eng/health/child/newbornscreening/newbornbloodspotscreening/information-for-professionals/a-practical-guide-to-newborn-bloodspot-screening-in-ireland.pdf
