Galactosaemia is an autosomal recessive disorder of galactose metabolism, most commonly due to deficiency of galactose-1-phosphate uridyltransferase (GALT). This leads to accumulation of galactose-1-phosphate and other toxic metabolites after ingestion of lactose (milk). It presents in the neonatal period and can rapidly become life-threatening if not recognised early.

🧠 Pathophysiology (Exam Gold)

🥛 Lactose → broken down into glucose + galactose
❌ GALT deficiency → impaired conversion of galactose to glucose
⬆️ Accumulation of galactose-1-phosphate → toxic to liver, brain, kidneys
🧴 Formation of galactitol → osmotic damage (e.g. cataracts)
🧠 Leads to hepatic dysfunction, encephalopathy, sepsis risk

⚠️ Clinical Presentation

👶 Presents in first few days after milk feeding starts
🍼 Poor feeding, vomiting
🟡 Jaundice (often prolonged or severe)
🧠 Lethargy, hypotonia
📉 Failure to thrive
🧫 Hepatomegaly
⚠️ Risk of E. coli sepsis (important exam clue)
👁️ Cataracts (due to galactitol accumulation)

🚨 Red Flag Pattern

👶 Sick neonate + jaundice + vomiting after milk feeds
🧪 ± hypoglycaemia, liver dysfunction

🧪 Investigations

🧪 Blood galactose levels – elevated
🧬 GALT enzyme assay
🧪 Liver function tests – deranged
🍬 Hypoglycaemia may be present
🧫 Blood cultures (look for E. coli)
🧬 Newborn screening (UK) detects galactosaemia

💊 Management (Urgent)

🚫 Immediately stop all lactose/galactose intake
🥛 Switch to lactose-free formula (e.g. soy-based)
💧 Supportive care (fluids, glucose if needed)
🧫 Treat sepsis promptly if suspected
📞 Early involvement of metabolic specialists

🥗 Long-Term Management

🚫 Lifelong galactose-restricted diet
🧪 Regular monitoring of metabolic control
🧠 Developmental follow-up (risk of learning difficulties)
👩 Potential complications: ovarian failure in females

👶 Newborn Screening (UK Context)

🧪 Included in heel prick test (day 5)
🎯 Early detection prevents severe complications

💡 Exam & Clinical Tips

🥛 Symptoms start after milk feeds = key clue
⚠️ Think galactosaemia in neonate with jaundice + sepsis
🧫 E. coli sepsis is highly associated
👁️ Cataracts can develop early
🚫 Early dietary exclusion is life-saving

From a clinical reasoning perspective, galactosaemia is a classic example of toxic substrate accumulation triggered by feeding. The neonatal liver is particularly vulnerable, leading to rapid onset of jaundice and coagulopathy. The association with E. coli sepsis is thought to relate to impaired immune function and altered gut environment. In UK practice, early recognition and immediate removal of galactose from the diet are critical, as untreated disease can quickly progress to liver failure, sepsis, and death.

The content on this website is provided for educational and informational purposes only to support exam preparation (e.g., MLA, MRCP, USMLE) and learning. This is NOT medical advice, diagnosis, treatment, or professional guidance. It does not replace consultation with a qualified healthcare professional, official guidelines (e.g., NICE, GMC, BNF), or supervised clinical practice. Always verify information with current, authoritative sources. Makindo and its contributors accept no liability for any reliance on this content, including errors, omissions, or any resulting harm, loss, or consequences. By using this site, you agree to these terms.

Galactosaemia