Galactosemia: Causes, Types, Symptoms, and Treatment

Introduction to Galactosemia

Galactosemia is a disorder in which the body is unable to metabolize galactose adequately. Galactose is a simple sugar that, in a correctly functioning body, is used for energy. In a person with galactosemia, the body cannot break down this simple sugar, causing the individual to become lethargic, lose energy and weight, and develop jaundice. If left untreated, the condition can lead to far worse complications, including cataracts, cirrhosis, intellectual disability, and even death (Berry & Walter, 2012). Galactosemia is therefore a very serious disorder. However, it can be managed by avoiding galactose — milk-based products are a primary source. This paper discusses galactosemia: what it is, what causes it, its disadvantages and potential advantages, how to minimize suffering from it, and how to treat it.

Galactosemia is a condition in which the GALT gene is mutated in a harmful way. The effect is that the body cannot absorb galactose properly, break it down, and derive energy from it. Instead, galactose remains in the body and accumulates, causing blockages in cells and tissues.

What Is Galactosemia?

Galactosemia is typically diagnosed very soon after birth. Nurses can perform a blood test using a single drop of blood taken from the heel of the newborn. An examination of the blood will reveal whether the GALT gene is mutated. If it is, the mother is quickly advised to stop breastfeeding. The reason is that breast milk contains lactose, which the body normally breaks down into galactose and glucose for energy. When the GALT gene is mutated, however, the body cannot metabolize the galactose produced from this breakdown. The only way to manage the condition is therefore to prevent galactose from entering the body — which means avoiding milk (Broomfield, Brain, & Grunewald, 2015).

Galactosemia is a genetic disorder that is typically inherited, meaning it is passed down from generation to generation. Cases in which galactosemia is acquired through other means exist but are rare. In the condition, the body is unable to break down lactose into the sugars — galactose and glucose — that it would normally metabolize for energy. It is also worth noting that the body can produce galactose on its own. When galactosemia is present, however, the person cannot consume lactose or galactose-containing products because the body cannot convert these sugars into energy. Galactose therefore accumulates in the cells and tissues and can cause infections, vomiting, and in severe cases, death.

Causes and Types

There are three recognized types of galactosemia. The first is galactose-1-phosphate uridyl transferase deficiency — the medical name for classic galactosemia and the most common form of the disorder (Haldeman-Englert, 2015).

The second type is galactose kinase deficiency, resulting from a mutation in the GALK gene. This form is less common than classic galactosemia and is not typically detected in standard newborn screenings. It is sufficiently rare that diagnosis can be difficult.

The third type is epimerase deficiency, caused by a mutation in the GALE gene. This form is generally less severe than the other two because only a partial inability to metabolize galactose is present. Impaired GALE activity can become problematic if complete inactivity develops, but this outcome is uncommon.

Conclusion

Galactosemia is a genetic disorder that affects the GALT, GALK, and GALE genes — most commonly the GALT gene — and results in the body's inability to metabolize galactose, which is found in lactose. Because the body cannot convert this sugar into energy, galactose accumulates in the tissues and cells, leading to complications that may include illness, intellectual impairment, and death. The disorder is usually identified at birth through routine neonatal blood screening. Because it is hereditary, family history can indicate whether a person is at elevated risk.