Inherited Metabolic Disorders

Inherited metabolic disorders are a group of genetic conditions in which the body is unable to properly convert food into energy due to missing or malfunctioning enzymes. These disorders are usually present from birth and can affect how the body processes proteins, carbohydrates, fats, or other substances. If not diagnosed and managed early, inherited metabolic disorders can lead to serious health problems, including developmental delays and organ damage.

Symptoms

Symptoms vary depending on the specific disorder and severity, but may include:

• Poor feeding or vomiting in infants

• Failure to thrive or poor weight gain

• Developmental delays

• Lethargy or extreme fatigue

• Seizures

• Muscle weakness

• Breathing difficulties

• Abnormal odor in urine, sweat, or breath

• Hypoglycemia or metabolic acidosis in severe cases

Causes

Inherited metabolic disorders are caused by genetic mutations that result in the absence or dysfunction of specific enzymes needed for metabolism. These mutations are typically inherited in an autosomal recessive or, less commonly, autosomal dominant or X-linked pattern. Common categories include:

• Amino acid metabolism disorders

• Carbohydrate metabolism disorders

• Fatty acid oxidation disorders

• Lysosomal storage disorders

• Mitochondrial disorders

Risk factors

• Family history of inherited metabolic disorders

• Parents who are carriers of a genetic mutation

• Consanguineous (related) parents

• Previous child affected by a metabolic disorder

Complications

• Intellectual disability or developmental delays

• Growth failure

• Liver, kidney, or heart damage

• Neurological complications such as seizures or movement disorders

• Life-threatening metabolic crises

• Reduced life expectancy in severe untreated cases

Prevention

While inherited metabolic disorders cannot be prevented after conception, early detection and management can significantly reduce complications:

• Newborn screening programs for early diagnosis

• Genetic counseling for families with a history of metabolic disorders

• Prenatal testing in high-risk pregnancies

• Strict dietary management when indicated

• Lifelong medical follow-up and monitoring

Early diagnosis through newborn screening and prompt treatment play a crucial role in improving outcomes and quality of life for individuals with inherited metabolic disorders.