Galactosemia (British galactosaemia, from Greek γαλακτόζη + αίμα, meaning galactose + blood, accumulation of galactose in blood) is a rare genetic metabolic disorder that affects an individuals ability to metabolize the sugar galactose properly. Galactosemia follows an autosomal recessive mode of inheritance that confers a deficiency in an enzyme responsible for adequate galactose degradation. Friedrich Goppert (1870–1927), a German physician,  first described the disease in 1917, with its cause as a defect in galactose metabolism being identified by a group led by Herman Kalckar in 1956. Galactosemia was the second disorder found to be detectable through newborn screening methods by Robert Guthrie.Its incidence is about 1 per 60,000 births for people of European ancestry. In other populations the incidence rate differs. Galactosaemia is about one hundred times more common (1:480 births) in the Irish Traveller population. Symptoms
Adults
Infants
Infants may appear asymptomatic at birth, however, upon ingestion of galactose a few days later (via breast and/or formula feeding), children start to experience life-threatening symptoms, which include:
poor feeding, and weight gain
vomiting and diarrhea
hepatocellular damage
lethargy, and hypotoniaProgression of this acute neonatal toxicity syndrome may include the development of sepsis, cataracts, and even pseudotumor cerebri (which may cause a bulging of fontanelle). Cause
Lactose in food (such as dairy products) is broken down by the enzyme lactase into glucose and galactose.
A galactosemia test is a blood test (from the heel of the infant) or urine test that checks for three enzymes that are needed to change galactose sugar that is found in milk and milk products into glucose, a sugar that the human body uses for energy. A person with galactosemia doesnt have one of these enzymes. This causes high levels of galactose in the blood or urine.Affected children can have serious, irreversible effects or even die within days from birth. It is important that newborns be screened for metabolic disorders without delay. Galactosemia can even be detected through NBS before any ingestion of galactose-containing formula or breast milk. Detection of the disorder through NBS does not depend on protein or lactose ingestion, and, therefore, it should be identified on the first specimen unless the infant has been transfused. A specimen should be taken prior to transfusion. The enzyme is prone to damage if analysis of the sample is delayed or exposed to high temperatures. The routine NBS is accurate for detection of galactosemia. Two screening tests are used to screen infants affected with galactosemia—the Beutlers test and the Hill test. The Beutlers test screens for galactosemia by detecting the level of enzyme of the infant. Therefore,  the ingestion of formula or breast milk does not affect the outcome of this part of the NBS, and the NBS is accurate for detecting galactosemia prior to any ingestion of galactose.