Summary about Disease
SECTION Holocarboxylase synthetase deficiency (HCSD) is a rare, inherited metabolic disorder in which the body is unable to properly utilize biotin. Biotin is a vitamin necessary for the function of several carboxylase enzymes, which are critical for various metabolic processes. HCSD results from a deficiency of the enzyme holocarboxylase synthetase, which is responsible for attaching biotin to these carboxylases, activating them. Without sufficient active carboxylases, the body cannot efficiently process proteins, carbohydrates, and fats.
Symptoms
SECTION Symptoms can vary in severity and age of onset. Common symptoms include:
Neurological problems: Seizures, developmental delay, hypotonia (poor muscle tone), ataxia (uncoordinated movements)
Skin problems: Skin rashes, eczema, alopecia (hair loss)
Metabolic problems: Lactic acidosis (build-up of lactic acid in the body), ketoacidosis, organic aciduria (increased levels of organic acids in urine), hyperammonemia (elevated ammonia levels in the blood)
Other symptoms: Feeding difficulties, lethargy, vomiting
Causes
SECTION HCSD is caused by mutations in the HLCS gene, which provides instructions for making holocarboxylase synthetase. The deficiency is inherited in an autosomal recessive manner, meaning both parents must carry a copy of the mutated gene for a child to be affected.
Medicine Used
SECTION 4. Medicine used The primary treatment for HCSD is high-dose oral biotin supplementation. Biotin is administered daily and helps to improve the function of the carboxylase enzymes. In some cases, other supportive therapies may be needed to address specific symptoms.
Is Communicable
SECTION No, HCSD is not communicable. It is a genetic disorder caused by inherited gene mutations and cannot be transmitted from person to person.
Precautions
SECTION
Genetic Counseling: Families with a history of HCSD should consider genetic counseling to assess the risk of having a child with the disorder.
Newborn Screening: Newborn screening programs can identify HCSD early, allowing for prompt treatment to prevent severe complications.
Dietary Management: Work with a dietician experienced in metabolic disorders to optimize diet and ensure adequate nutrient intake.
How long does an outbreak last?
SECTION HCSD is not an infectious disease and does not have outbreaks. It is a chronic condition that requires lifelong management.
How is it diagnosed?
SECTION Diagnosis typically involves:
Newborn screening: Many states include HCSD in their newborn screening programs, which involves testing a blood sample for elevated levels of certain metabolites.
Clinical evaluation: Review of the patient's symptoms and medical history.
Biochemical testing: Measuring the activity of carboxylase enzymes in blood or tissue samples. Elevated levels of specific organic acids in urine can also be indicative.
Genetic testing: Sequencing the HLCS gene to identify mutations.
Timeline of Symptoms
SECTION 9. Timeline of symptoms The timeline of symptoms can vary.
Early-onset form: Symptoms typically appear within the first few weeks or months of life.
Late-onset form: Symptoms may not appear until later in infancy or childhood. The severity of symptoms can also range from mild to life-threatening.
Important Considerations
SECTION
Early diagnosis and treatment are crucial: Early biotin supplementation can significantly improve the prognosis and prevent severe complications.
Lifelong management is required: Biotin supplementation must be continued throughout life.
Regular monitoring is necessary: Patients need regular monitoring to assess their response to treatment and adjust the dosage of biotin as needed.
Multidisciplinary care is important: Management requires a team of healthcare professionals, including a metabolic specialist, neurologist, dermatologist, and dietician.