E74.2 Disorders of galactose metabolism

Name of the Condition

• Disorders of galactose metabolism (ICD-10 Code E74.2)

Summary

Disorders of galactose metabolism are a group of conditions that impair the body's ability to process galactose, a sugar derived from lactose (milk sugar). These disorders disrupt normal metabolic pathways, leading to the accumulation of galactose or its byproducts, which can cause symptoms and complications if not managed appropriately.

Causes

Disorders of galactose metabolism are typically caused by genetic mutations affecting enzymes or transporters involved in galactose breakdown. The most common form, classic galactosemia, results from a deficiency of the enzyme galactose-1-phosphate uridylyltransferase (GALT). Other forms may involve defects in enzymes like galactokinase (GALK) or UDP-galactose-4-epimerase (GALE), each leading to distinct metabolic disruptions.

Risk Factors

• Genetic predisposition or family history of galactose metabolism disorders.
• Newborns or infants, as symptoms often present early with dietary exposure to lactose.
• Certain ethnic or population groups may have higher prevalence of specific subtypes.

Symptoms

• Jaundice (yellowing of the skin or eyes) in infants.
• Poor feeding, vomiting, or diarrhea after consuming milk or dairy products.
• Lethargy, irritability, or failure to thrive.
• Cataracts (clouding of the eye lens) in some cases.
• Developmental delays or intellectual disability if untreated.

Diagnosis

Diagnosis involves clinical evaluation of symptoms, dietary history, and laboratory testing. Newborn screening programs often detect elevated galactose levels or enzyme deficiencies. Confirmatory tests may include measuring enzyme activity (e.g., GALT, GALK) or genetic testing to identify specific mutations. Urine tests for galactitol (a byproduct) or blood tests for galactose-1-phosphate levels may also be used.

Treatment Options

Treatment primarily involves strict dietary restriction of galactose, which requires eliminating lactose-containing foods (e.g., milk, cheese, breast milk) and using galactose-free formulas. Close monitoring of growth, development, and organ function (e.g., liver, eyes) is essential. In some cases, supplements or medications may address specific complications, such as cataracts.

Prognosis and Follow-Up

With early diagnosis and strict dietary management, prognosis is generally good, though long-term complications (e.g., speech delays, learning difficulties) may occur. Regular follow-up with a metabolic specialist, dietitian, and ophthalmologist is recommended to monitor growth, cognitive development, and organ health. Lifelong adherence to the galactose-restricted diet is typically required.

Complications

• Cataracts (due to galactitol accumulation in the lens).
• Liver damage or cirrhosis from prolonged galactose exposure.
• Speech or language delays.
• Intellectual disability or learning difficulties if untreated.
• Ovarian insufficiency in females (a late complication).

Lifestyle & Prevention

• Strict adherence to a galactose-restricted diet, avoiding all lactose-containing foods.
• Careful reading of food labels to identify hidden sources of galactose (e.g., whey, casein).
• Breastfeeding may require supplementation with a galactose-free formula under medical guidance.
• Regular monitoring of nutritional status and growth to prevent deficiencies.

When to Seek Professional Help

Seek immediate medical attention if an infant shows signs of jaundice, poor feeding, vomiting, or lethargy after consuming milk or dairy products. Contact a healthcare provider if symptoms worsen or new complications (e.g., cataracts, developmental delays) arise. Early intervention is critical to prevent long-term damage.

Tips for Medical Coders

When coding for disorders of galactose metabolism (E74.2), ensure documentation supports the diagnosis, including clinical findings (e.g., jaundice, cataracts), dietary history, and laboratory results (e.g., elevated galactose levels, enzyme deficiency). Specify the subtype if known (e.g., classic galactosemia, galactokinase deficiency) when additional detail is available, but use E74.2 for general cases. Document any associated complications (e.g., cataracts, liver disease) separately if they require additional coding.