Inherited Metabolic Disorders
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Inherited metabolic disorders result from alterations in specific genes that impact the body’s metabolic processes. Various gene mutations give rise to distinct types of inherited metabolic disorders, with these genetic changes typically being inherited from both parents. However, in some cases, the mutation may originate solely from one parent, most commonly the mother. These conditions are also referred to as inborn errors of metabolism.
Metabolism, a complex series of chemical reactions essential for sustaining life, encompasses several crucial functions:
- Energy Production: Special enzymes break down food or specific chemicals, enabling the body to immediately use them as fuel or store them for later use.
- Synthesis or Elimination of Substances: Certain chemical processes generate substances essential for the body, while other processes break down substances that are no longer needed.
When these processes fail to function correctly, a metabolic disorder arises. The root cause could be a deficiency or absence of a particular enzyme or other underlying issues. Inherited metabolic disorders are categorized based on the affected substance and whether it accumulates excessively due to breakdown impairment or is deficient or absent.
Symptoms
Numerous inherited metabolic disorders result from various genes. The manifestation of symptoms is contingent upon the specific disorder and its severity.
Some instances of inherited metabolic disorders comprise:
- Gaucher disease.
- Hunter syndrome.
- Krabbe disease.
- Porphyria.
- Tay-Sachs disease.
- Wilson’s disease.
- Niemann-Pick.
- Phenylketonuria (PKU).
- Maple syrup urine disease.
- Metachromatic leukodystrophy.
- Familial hypercholesterolemia.
- Mitochondrial Encephalopathy with Lactic Acidosis and Stroke-like Episodes (MELAS).
Symptoms of typical inborn errors of metabolism encompass:
- Seizures.
- Abdominal pain.
- Lethargy (low energy).
- Weight loss.
- Poor appetite.
- Delay development.
- Growth problems.
- Unusual odors in urine, sweat, or breath.
If you have any worries regarding the growth and development of your child or your own well-being, it is advisable to consult with your doctor.
Causes
Inherited metabolic disorders result from alterations in specific genes influencing metabolism. Distinct gene mutations give rise to various types of inherited metabolic disorders, with these genetic changes typically being inherited from both parents. However, in certain instances, the mutation may originate solely from one parent, most commonly the mother. The array of inherited metabolic disorders caused by diverse genes encompasses hundreds of different conditions.
Risk factors
The likelihood of inheriting a metabolic disorder is elevated if either or both parents carry the gene mutation responsible for the condition. In certain scenarios, prospective parents may opt for carrier testing before conceiving. This screening can detect specific gene mutations in parents that might increase the probability of their future children having particular inherited metabolic disorders.
Diagnosis
Certain inherited metabolic disorders can be identified during prenatal testing, while others may be diagnosed through routine newborn screening tests conducted shortly after birth. Alternatively, some disorders only become apparent when a child or adult exhibits symptoms.
To determine whether you or your child has an inherited metabolic disorder, you may undergo:
- Physical assessment: A thorough physical examination will be conducted, encompassing discussions about your or your child’s symptoms, along with a review of medical history. Family history may also be explored.
- Diagnostic tests: Blood and urine tests are employed to assess the functionality of metabolism. Additional tests may be recommended depending on the situation.
- Genetic testing: Genetic testing is capable of identifying the specific inherited metabolic disorder affecting you or your child. If a family member has such a disorder, specialists often recommend genetic testing and counseling for other relatives. For prospective parents, preconception screening or carrier testing may be chosen before pregnancy. This test can pinpoint certain gene changes in parents, heightening the awareness of potential risks for specific inherited metabolic disorders.
- Specialist examinations: Some inherited metabolic disorders may elevate the risk of associated conditions like heart, vision, or hearing problems. Referral to specialists may be suggested accordingly.
- Genetic counseling: Genetic counseling involves discussions about newborn screening and other genetic tests. It also provides information on the likelihood of an inherited metabolic disorder affecting future children.
Treatment
The course of treatment is contingent upon the specific type and severity of the inherited metabolic disorder. Given the diversity of these disorders, treatment approaches can vary significantly.
Examples of treatments encompass special diets, enzyme replacement, vitamin therapy, medications, and, in certain cases, liver transplants. Hospitalization may be necessary as the initial step in care. However, for some types of inherited metabolic disorders, no specific treatments are currently available.
Due to their rarity and complexity, inherited metabolic disorders may require consultation with various experts based on the type, severity, and the age of the affected individual. This may involve specialists in:
- Nutrition.
- Nervous system.
- Endocrine and metabolic disorders.
- Medical genetics.
- Pediatrics and developmental pediatrics.
- Ear, nose and throat (ENT).
- Eyes and vision.
- Cardiovascular system.
- Gastrointestinal system.
- Renal system.
Continuous and lifelong care, involving regular doctor visits, is crucial for addressing issues at an early stage and making necessary adjustments to the treatment as required.
