Metabolic disorders

What are Inherited Metabolic Disorders?
Inherited metabolic disorders are genetic conditions that interfere with the body's metabolism. Metabolism is the complex set of chemical reactions your body uses to produce energy.

In these disorders, a defective gene causes an enzyme deficiency. This leads to a dangerous buildup of substances in the body or a lack of essential substances.

There are hundreds of different metabolic disorders. Most are rare individually, but collectively they are quite common.

Symptoms

Symptoms vary widely depending on the specific metabolic problem. In severe cases, symptoms appear shortly after birth. In milder forms, they may not appear until childhood or adulthood.

Acute Symptoms (Sudden Onset)

• Vomiting and poor appetite.
• Abdominal pain.
• Abnormal odor in urine, breath, or sweat.
• Weight loss or failure to gain weight (Failure to thrive).
• Jaundice (yellowing of skin/eyes).
• Seizures or Coma.

Chronic Symptoms (Long-term)

• Developmental delay or learning disabilities.
• Muscle weakness.
• Vision or hearing problems.
• Heart or liver enlargement.

Causes: The Genetics

[Image of Autosomal Recessive Inheritance pattern]

These disorders are usually inherited from both parents. This pattern is called Autosomal Recessive Inheritance.

• The Mechanism: Special enzymes break down food for fuel. If a gene is defective, the body cannot make the enzyme.
• The Result: Toxic chemicals build up in the blood, or the body cannot produce energy.
• The Carrier: Parents often do not have the disease themselves; they are "carriers" of the defective gene.

Common Types of Disorders

While there are hundreds of types, some of the most well-known include:

• Phenylketonuria (PKU): Inability to break down the amino acid phenylalanine. Requires a strict diet.
• Tay-Sachs Disease: A fatal disorder that destroys nerve cells in the brain and spinal cord.
• Galactosemia: Inability to break down the sugar galactose (found in milk).
• Mitochondrial Disorders: Problems with the "power plants" of cells, affecting energy production.
• Gaucher Disease: Inability to break down a specific type of fat, which accumulates in the liver, spleen, and bone marrow.

Diagnosis

Early diagnosis is crucial to prevent permanent damage.

• Newborn Screening: In many countries, all babies are tested at birth (via a heel prick blood test) for common metabolic disorders like PKU.
• Genetic Testing: DNA tests to identify specific gene mutations.
• Blood & Urine Tests: To check for abnormal levels of metabolites (amino acids, organic acids).
• Tissue Biopsy: Taking a sample of liver or muscle to test enzyme activity.

Treatment

Treatment is lifelong and aims to manage the condition, as genetic defects cannot be "cured."

1. Dietary Changes

For many disorders, Diet is Medicine.

• Elimination: Removing foods the body cannot process (e.g., removing milk for Galactosemia).
• Supplementation: Taking enzymes or vitamins to help the metabolism work.

2. Medical Treatments

• Enzyme Replacement Therapy: IV infusions to replace the missing enzyme (used in Gaucher disease).
• Detoxification: Using medications to remove toxic byproducts from the blood.
• Organ Transplant: Liver or bone marrow transplants can sometimes provide a cure for specific disorders.

⚠️ EMERGENCY WARNING
Metabolic crises can be triggered by illness or fasting. If a person with a known metabolic disorder starts vomiting or becomes lethargic, seek emergency medical attention immediately.

Disclaimer: The content provided on this blog is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician regarding any medical condition.