Introduction
Beta-ketothiolase deficiency(Beta-Ketothiolase deficiency) is also known as 2-methyl-3-hydroxybutyric acidemia or mitochondrial acetoacetyl-CoA thiolase deficiency, which is caused by the lack of acetoacetyl-CoA thiolase (T2) in the mitochondria. This causes the patient's body to be unable to metabolize and decompose ketone and isoleucine in the body. The patient has intermittent ketoacidosis, but there are no clinical symptoms during the attack. In patients with β-ketothiolase deficiency, once ketoacidemia is attacked, it is often quite serious, sometimes accompanied by lethargy or coma. Some patients may also have sequelae of nervous system damage. If the disease occurs repeatedly, the patient's intelligence and motor skills will gradually lose as they grow older. The incidence of β-ketothiolase deficiency is less than 100,000.
The name of the Chinese medicine disease β-ketothiolase deficiency English name Beta-Ketothiolase deficiency The common cause of the common group from 5 months to 2 years old is induced by gastroenteritis and febrile diseases, such as respiratory tract infection, measles, or otitis media. Common symptoms such as vomiting, dehydration, shortness of breath or difficulty breathing, low muscle tone, and sometimes lethargy can lead to coma
Clinical manifestation
Patients with β-ketothiolase deficiency usually have no clinical symptoms during neonatal and early childhood. However, most patients experience the first ketoacidemia between 5 months and 2 years of age. Ketoacidemia is usually induced by gastroenteritis and febrile diseases such as respiratory infections, measles, or otitis media. The more dangerous clinical symptoms of ketoacidemia include vomiting, dehydration, shortness of breath or difficulty breathing, low muscle tone, and sometimes lethargy can lead to coma. Some patients develop symptoms of convulsions. The patient's blood gas analysis will show severe metabolic acidosis values combined with local respiratory compensation.
diagnosis method
Urine organic acid analysis and blood tandem mass spectrometry analysis can be used to determine whether the case has β-ketothiolase deficiency. The presence of 2-methyl-3-hydroxybutyrate, tiglylglycine and 2-methylaceteoacetate is usually found in the urine of patients. The rise of tiglylcarnitine and 2-methyl-3-hydroxybutyrylcarnitine (C5OH and C5: 1-carnitine) was also observed by blood tandem mass spectrometry. Although hypoglycemia or hyperglycemia cannot be used as a basis for excluding patients with β-ketothiolase deficiency, in general, patients with this condition usually have normal blood sugar levels. In addition, the detection of enzyme activity and gene detection in skin sections can also be used as one of the methods for confirming diagnosis.
Pathogenesis
This disease is caused by a mutation in the ACAT1 gene and belongs to a genetic disorder that is recessive in the body. Individual parents each carry a normal chromosomal recessive mutation and do not show symptoms. Parents with a factor of 25% have a 2% chance of giving birth to a child with β-ketothiolase deficiency, and the chance of giving birth to an unaffected child is 50%. The chance of being a child is 25%.
Preventive treatment
Patients need a slightly restricted protein (1.5-2.0 g/kg/day) to avoid taking too much iso-alanine and avoid taking a high-fat diet. Administration of L-carnitine supplements is helpful to the patient. In patients with acute attacks, protein restriction and prophylactic infusion of glucose are required to avoid ketoacidemia. Patients should avoid fasting in normal times. Some children may need to continue to use a low-protein diet and need to perform regular urine tests to monitor the patient's ketoacid value.
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