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PubMed This is a summary of 13 peer-reviewed journal articles Updated
Pediatrics

Recognizing Acute Symptoms and Risks

At a Glance

Newborns with classic galactosemia develop acute, life-threatening symptoms like jaundice, lethargy, and a high risk of E. coli sepsis when fed breast milk or standard formula. Immediate removal of galactose by switching to a soy-based formula is critical to stabilize the infant.

When a newborn with Classic Galactosemia consumes breast milk or standard formula, the toxic buildup of galactose-1-phosphate (Gal-1-P) occurs very quickly [1]. If the condition is not caught immediately by newborn screening, a baby will show signs that their body is struggling to handle milk [2].

Recognizing Acute Symptoms

These symptoms usually appear within the first few days of life and can include:

  • Jaundice: A yellowing of the skin and eyes caused by the liver being under stress [3].
  • Lethargy: Extreme sleepiness or being very “floppy” and difficult to wake for feedings [4].
  • Feeding Intolerance: Poor feeding, frequent vomiting, or difficulty staying awake for feeds [4].
  • Liver Dysfunction: The liver may become enlarged (hepatomegaly) or begin to fail, which doctors see in blood tests showing poor clotting or high enzyme levels [5][6].
  • Cataracts: Clouding of the lens of the eye, which can occur very early due to the rapid accumulation of a related byproduct called galactitol [7].

While these symptoms are frightening, they typically begin to resolve rapidly once the baby is switched to a galactose-free diet, such as a soy-based formula [8][2].

The Critical Risk: E. coli Sepsis

One of the most serious risks for a newborn with untreated galactosemia is a life-threatening blood infection called E. coli sepsis [9][10]. For reasons researchers are still studying, the buildup of galactose in the body makes it much easier for E. coli bacteria to grow and spread [9][11].

This is particularly tricky because the symptoms of sepsis (infection) and the symptoms of galactosemia itself look almost identical. Because of this overlap, it is standard for doctors to treat sick newborns with galactosemia with antibiotics immediately, even before infection results are back [6][4].

Moving Toward Stability

The most important step in stabilizing a baby with Classic Galactosemia is the total removal of galactose from their diet [8][12].

A Note on Breastfeeding and Testing: A positive newborn screen is only a “flag.” Sometimes, babies have a milder variant (like Duarte Galactosemia) that does not require stopping breast milk. However, until confirmatory lab tests come back, doctors will ask you to temporarily stop breastfeeding. During this waiting period, it is highly recommended to pump and safely store your breast milk (“pump and dump”) to maintain your milk supply. If the tests confirm the milder Duarte variant, or if it was a false positive, you will be able to resume breastfeeding.

Early diagnosis through screening and the immediate switch to the correct formula is the most powerful “medicine” your baby can receive for these early symptoms [8][13].

Common questions in this guide

What are the first signs of classic galactosemia in a newborn?
The earliest signs usually appear within days of drinking breast milk or standard formula. These include jaundice, extreme sleepiness, poor feeding, and frequent vomiting.
Why is E. coli sepsis a risk for babies with galactosemia?
The toxic buildup of galactose in the body creates an environment that makes it much easier for E. coli bacteria to grow and spread. Because sepsis and galactosemia symptoms look similar, doctors often treat sick newborns with antibiotics immediately.
How do you treat acute symptoms of classic galactosemia?
The primary and most critical treatment is the immediate removal of all galactose from the baby's diet. Doctors will typically switch the infant to a galactose-free, soy-based formula to rapidly resolve symptoms.
Should I stop breastfeeding if my baby has a positive newborn screen for galactosemia?
Doctors will ask you to temporarily stop breastfeeding while waiting for confirmatory test results. During this time, you should pump and safely store your milk to maintain your supply in case the test indicates a milder variant or is a false positive.
Can classic galactosemia cause eye problems in babies?
Yes, babies with this condition can develop cataracts, which is a clouding of the eye's lens. This happens very early due to the rapid buildup of a galactose byproduct called galactitol in the body.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Has my baby been screened for E. coli sepsis, and do we have the results of blood cultures?
  2. 2.Are my baby's liver function tests and blood clotting levels showing signs of improvement since we stopped milk?
  3. 3.Has an ophthalmologist examined my baby to check for early signs of cataracts?
  4. 4.If the newborn screen is not yet confirmed, how can the hospital support me in pumping to maintain my breast milk supply?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (13)
  1. 1

    Galactose-1-phosphate inhibits cytochrome c oxidase and causes mitochondrial dysfunction in classic galactosemia.

    Machado CM, de-Souza-Ferreira E, Silva GFS, et al.

    Biochimica et biophysica acta. Molecular basis of disease 2024; (1870(7)):167340 doi:10.1016/j.bbadis.2024.167340.

    PMID: 38986816
  2. 2

    All aspects of galactosemia: a single center experience.

    Akgun A, Dogan Y

    Journal of pediatric endocrinology & metabolism : JPEM 2023; (36(1)):29-35 doi:10.1515/jpem-2022-0308.

    PMID: 36399011
  3. 3

    A case of classic galactosemia manifesting as neonatal early and profound indirect hyperbilirubinemia.

    Kavehmanesh Z, Torkaman M, Beiraghdar F

    Turk pediatri arsivi 2020; (55(3)):316-319 doi:10.14744/TurkPediatriArs.2019.21298.

    PMID: 33061763
  4. 4

    Galactosemia.

    Cerone J, Rios A

    Pediatrics in review 2019; (40(Suppl 1)):24-27 doi:10.1542/pir.2018-0150.

    PMID: 31575690
  5. 5

    Inborn Errors of Metabolism with Hepatopathy: Metabolism Defects of Galactose, Fructose, and Tyrosine.

    Demirbas D, Brucker WJ, Berry GT

    Pediatric clinics of North America 2018; (65(2)):337-352 doi:10.1016/j.pcl.2017.11.008.

    PMID: 29502917
  6. 6

    Transient Cytopenias as a Rare Presentation of Classic Galactosemia.

    Gianniki M, Nikaina I, Avgerinou G, et al.

    Cureus 2022; (14(3)):e23101 doi:10.7759/cureus.23101.

    PMID: 35464534
  7. 7

    Results of the ACTION-Galactosemia Kids Study to Evaluate the Effects of Govorestat in Pediatric Patients with Classic Galactosemia.

    Bailey E, Phan H, Ahmad A, et al.

    Journal of clinical pharmacology 2025; (65(5)):575-587 doi:10.1002/jcph.6170.

    PMID: 39569553
  8. 8

    Screening for galactosemia: is there a place for it?

    Kotb MA, Mansour L, Shamma RA

    International journal of general medicine 2019; (12()):193-205 doi:10.2147/IJGM.S180706.

    PMID: 31213878
  9. 9

    Novel Mutation in GALT Gene in Galactosemia Patient with Group B Streptococcus Meningitis and Acute Liver Failure.

    Grama A, Blaga L, Nicolescu A, et al.

    Medicina (Kaunas, Lithuania) 2019; (55(4)) doi:10.3390/medicina55040091.

    PMID: 30987402
  10. 10

    Galactosaemia occurring in association with primary ovarian insufficiency, Addison's disease and chronic myeloid leukaemia.

    Khoury B, Shakir MK, Hoang TD

    BMJ case reports 2021; (14(8)) doi:10.1136/bcr-2021-244788.

    PMID: 34433538
  11. 11

    Coagulopathy in Neonates With Classic Galactosemia: A Life-Threatening Yet Underrecognized Complication.

    Gagen JK, Tinker RJ, Phillips JA, Furuta Y

    Journal of pediatric health care : official publication of National Association of Pediatric Nurse Associates & Practitioners 2026; doi:10.1016/j.pedhc.2026.02.001.

    PMID: 41746225
  12. 12

    Qualitative interviews with adults with Classic Galactosemia and their caregivers: disease burden and challenges with daily living.

    Randall JA, Sutter C, Wang S, et al.

    Orphanet journal of rare diseases 2022; (17(1)):138 doi:10.1186/s13023-022-02287-9.

    PMID: 35346295
  13. 13

    Primary ovarian insufficiency in classic galactosemia: current understanding and future research opportunities.

    Thakur M, Feldman G, Puscheck EE

    Journal of assisted reproduction and genetics 2018; (35(1)):3-16 doi:10.1007/s10815-017-1039-7.

    PMID: 28932969

This page provides educational information about acute galactosemia symptoms in newborns. Always consult a pediatrician or seek emergency medical care immediately if your baby exhibits poor feeding, lethargy, or jaundice.

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