classic galactosemia

Cataract

Clouding of the lens of the eye (cataract) develops because a galactose byproduct accumulates in the lens. With early dietary treatment, cataracts often resolve.

Intellectual disability

Despite early treatment, galactosemia often leaves lasting effects on thinking and learning. Many people have some degree of cognitive impairment that ranges from mild learning difficulty to more significant intellectual disability.

Premature ovarian insufficiency

Many women and girls with classic galactosemia develop primary ovarian insufficiency, meaning the ovaries stop working as expected at an early age. This is one of the most common long-term complications.

Failure to thrive

Affected babies often fail to gain weight and grow normally (failure to thrive) because of feeding intolerance and the metabolic toxicity.

Feeding difficulties

Newborns with classic galactosemia often cannot tolerate their feeds, because they are unable to break down the galactose in milk.

Jaundice

Yellowing of the skin and eyes (jaundice), often prolonged, is a frequent early sign of classic galactosemia in newborns.

Decreased liver function

Trouble with how the liver works (liver dysfunction) is a hallmark of untreated classic galactosemia in the newborn period; in one neonatal series it affected every baby.

Hepatomegaly

An enlarged liver (hepatomegaly) is one of the most consistent early signs, reflecting the toxic effect of galactose byproducts on the liver.

Vomiting

Vomiting after milk feeds, along with poor feeding, is a typical early symptom that brings the baby to medical attention.

Diarrhea

Diarrhea can be part of the early picture of classic galactosemia in newborns.

Reduced erythrocyte galactose-1-phosphate uridylyltransferase activity

Classic galactosemia is caused by too little of the enzyme galactose-1-phosphate uridyltransferase (GALT), which the body needs to break down galactose. Low GALT activity measured in red blood cells is the key finding that confirms the condition.

Sepsis

Babies with classic galactosemia have an increased risk of a serious bloodstream infection, most often from the bacterium Escherichia coli (E. coli sepsis).

Hypoglycemia

Low blood sugar (hypoglycemia) can occur in newborns with classic galactosemia.

Decreased circulating vitamin D concentration

People with classic galactosemia can develop nutritional shortfalls, including low vitamin D and calcium, which matter for bone health over the long term.

Action tremor

A tremor (shaking of the hands or limbs during movement) is a long-term complication that affects a meaningful share of people with classic galactosemia.

Ataxia

Over the long term, galactosemia can affect the brain's movement-control systems, producing problems with balance and coordination (ataxia) and sometimes tremor, even in people who have followed the diet.

Speech apraxia

Even when galactose is removed from the diet early, many people with galactosemia develop a motor speech disorder (apraxia of speech), where the brain struggles to coordinate the movements needed to speak clearly.

Global developmental delay

Many children show developmental delay and later cognitive and speech difficulties. These long-term effects can persist despite a well-managed diet, which is why galactosemia is not fully prevented by diet alone.

Hepatic failure

Untreated, classic galactosemia can lead to sudden, severe liver failure in early infancy, which can be life-threatening.

Osteoporosis

Thinning and weakening of the bones (osteoporosis) can develop in people with classic galactosemia over the long term.

Classic galactosemia

Diagnosed using: GALT enzyme activity in red blood cells.

Classic galactosemia

Diagnosed using: newborn screening for galactosemia.

Classic galactosemia

Diagnosed using: GALT gene testing.

galactose-restricted diet

The cornerstone of treatment for classic galactosemia is a galactose-restricted diet, which removes the galactose the body cannot break down. Started early, it can reverse the early cataracts and other complications, though it does not prevent every long-term effect.

Used to help with: Classic galactosemia.