Pediatric hereditary fructose intolerance
Introduction
Introduction to hereditary fructose intolerance in children Hereditary fructose intolerance is a congenital metabolic disorder caused by defects in fructalose (fructalose-1,6-diphosphatealdolase). There are three obstacles to the fructose metabolic pathway caused by autosomal recessive inheritance: 1. Fructose kinase deficiency (or idiopathic fructoseuria, essential fructosuria). 2. Hereditary fructose intolerance (hereditaryfructoseintolerance). 3. fructose-1, 6-diphosphatase deficiency. basic knowledge The proportion of illness: 0.001% Susceptible people: children Mode of infection: non-infectious Complications: diarrhea, dehydration, shock, liver cirrhosis, jaundice, edema, ascites, hypoglycemia
Cause
Pediatric hereditary fructose intolerance etiology
Causes:
The disease belongs to autosomal recessive genetic disease. The patient's liver fructose-1-phosphate aldolase is detected by 14C-labeled fructose, which is found to be a normal 0-12%, showing a significant decrease.
Prevention
Pediatric hereditary fructose intolerance prevention
(1) Avoid marriage by close relatives
The incidence of genetic diseases is significantly higher among children born to close relatives.
(2) Conduct genetic counseling
For those who have had miscarriage, stillbirth, stillbirth, malformation or chromosomal abnormalities or hereditary diseases, if you want to give birth again, you need to conduct genetic counseling. If you want to have a genetic disease for both men and women, you should have a genetic counseling before pregnancy.
(3) Prenatal diagnosis through B-mode ultrasound or amniocentesis, early detection of hereditary diseases, timely termination of pregnancy.
(4) Avoid the influence of adverse environmental factors
Chemical, physical, and biological factors can distort chromosomes.
Complication
Pediatric hereditary fructose intolerance complications Complications diarrhea dehydration shock cirrhosis jaundice edema ascites hypoglycemia
Vomiting, diarrhea can cause dehydration, shock, acute liver failure, cirrhosis, jaundice, edema, ascites and bleeding tendency, coma, etc., or hypoglycemia, convulsions and other symptoms, weight loss, liver and so on.
Symptom
Pediatric hereditary fructose intolerance symptoms Common symptoms Dehydration diarrhea, cold sweat, abdominal pain, hypoglycemia, bleeding, edema, jaundice, loss of appetite, liver failure
The age of onset is related to the dietary composition used. Since most of the milk contains sucrose, the newborn children who are given artificial feeding after birth often have vomiting, diarrhea, dehydration, shock and bleeding tendency in 2 to 3 days. Symptoms of dysfunction; breast-fed infants are given a sucrose or fructose-containing food supplement in the infant period. Within 30 minutes of feeding, vomiting, abdominal pain, cold sweat, and symptoms of hypoglycemia such as coma and convulsions occur. , the child quickly developed loss of appetite, diarrhea, weight loss, liver, jaundice, edema and ascites, etc., some children will automatically refuse to eat in the baby period due to repeated eating "sweet" symptoms, this protective Behavior can make children grow up to adulthood, and a small number of children may die of progressive liver failure due to lack of timely diagnosis and treatment.
Examine
Pediatric hereditary fructose intolerance test
1. Blood biochemical examination In the presence of acute symptoms, the child should present hypoglycemia, while blood phosphorus, blood potassium is transiently reduced, serum fructose, lactic acid, pyruvic acid and uric acid are increased.
In the case of hypoglycemia, it is also seen that the serum insulin level is decreased, while the concentrations of glucagon, adrenaline and growth hormone are increased. With the changes of these hormones, plasma free fatty acids are significantly increased, which is different from normal people, fructose-1. 6-diphosphatase deficiency (autosomal recessive inheritance, its clinical manifestations resemble fructose intolerance, mainly liver enlargement) can cause hypoglycemia after eating fructose and when starving, so easy to accumulate with glycogen The disease, "ketohypoglycemia" and the disease are confused.
The detection of serum bilirubin, transaminase and coagulation factors contributes to the diagnosis and treatment of acute liver failure.
2. Urine biochemical examination should be used to detect urine fructose in children with suspected acute illness. Children who continue to eat fructose often have renal tubular acidosis and Fanconi syndrome-like tubular reabsorption disorder. Therefore, in response to urine pH, Proteins, amino acids and bicarbonates are tested.
3. Fructose tolerance test The fructose, glucose, inorganic phosphorus, uric acid and transaminase in the blood can be diagnosed after intravenous injection of fructose 200-250mg/kg. The test should be carried out several weeks after the condition is stable.
4. Enzymatic examination can be performed using liver, kidney or intestinal mucosal biopsy, but not required for diagnosis.
B-ultrasound can detect liver enlargement, ascites and other diseases.
Diagnosis
Diagnosis and identification of hereditary fructose intolerance in children
The diagnosis can be based on:
1. Clinical features After removing fructose from food, the clinical symptoms disappear within a few hours.
2. The fructose tolerance test shows that blood glucose and blood phosphorus decrease rapidly, while fructose, fatty acid and lactic acid increase, but this test is easy to cause hypoglycemia, so it should be used with caution, and the amount of fructose used should be reduced. 0.5g/kg, the venous volume is halved, and children can also take 3g/m2 orally.
3. Biopsy liver, enzyme assay in intestinal mucosa showed significant reduction in enzyme activity.
The disease should be distinguished from pyloric obstruction, gastroenteritis, sepsis, severe hepatitis and other disorders of glucose metabolism.
