Propionic Acidemia

Propionic Acidemia
Body Parts: Whole Body
Medical Subjects: Children's Health Blood Genetic disease

What Is Propionic Acidemia?

Propionic acidemia is a genetic disease, belonging to one of organic acidemia. Genetic defects cause the deficiency of metabolic enzymes (propionyl coenzyme and A carboxylase) in the body, resulting in abnormal metabolism of branched-chain amino acids and even-chain fatty acids, abnormal accumulation of propionic acid and its metabolite precursor in the body, and impacts and damages the body.

Most patients with propionic acidemia get sick within one month after birth. The typical manifestations of acute phase are feeding difficulty, vomiting, lethargy, and epileptic seizure. The earlier the onset, the more serious the condition, which can be life-threatening. If the diagnosis and treatment are not timely, it may lead to irreversible nerve damage, mental retardation, blindness and other permanent sequelae.

Propionic acidemia is uncommon and is a rare condition. The prevalence of propionic acidemia varies across races and regions, for example, in the United States, one case per 100,000 live births, Saudi Arabia, one case per 2,000 to 5,000 live births, and the Inuit of Greenland, one case per 1,000 live births.


What Is The Cause Of Propionic Acidemia?

What is the aetiology of propionic acidemia?

  • Propionic acidemia is a congenital genetic disease caused by genetic problems. Genetic defects cause the loss of metabolic enzyme activity in the body, making abnormal accumulation of propionic acid and its metabolite precursor, leading to propionic acidemia, causing a series of symptoms and organ damage.

Is propionic acidemia contagious?

  • Propionic acidemia is a congenital hereditary disease and is not contagious.

Can propionic acidemia be inherited?

Propionic acidemia is hereditary, propionic acidemia is inherited, and it follows the law of autosomal recessive inheritance. Can be simply understood as:

  • If both parents have no disease manifestations but both carry disease-causing genes, the offspring have a 25% chance of getting sick.
  • If one parent falls sick and the other carries the disease-causing gene, the offspring have a 50% chance of getting sick.

What Symptom Does Propionic Acidemia Have?

What symptom and expression does propionic acidemia have?

  • Propionic acidemia differs greatly in manifestation due to different degrees of defects in metabolic enzymes in the body.
  • Partially infants with propionic acidemia present with facial malformations such as a high forehead, a wide bridge of the nose, epicanthous folds, a long, smooth middle and triangular mouth.
  • Most of newborns are normal at birth and gradually develop vomiting, lethargy, convulsions, seizures, psychomotor abnormalities, ketosis, or hypoglycemia. The earlier the disease appears, the more serious the condition will become. The most serious ones will have difficulty in feeding and life-threatening metabolic acidosis and hyperammonemia soon after birth, making the newborns die a few days after birth.
  • Most of the children who started the disease in infancy manifested as feeding difficulties, developmental delay, convulsions, abnormal movement, and often induced acute attack due to fever, high protein diet, infection and other reasons.

What complication does propionic acidemia have?

Abnormal accumulation of propionic acid and its metabolite precursor in vivo can cause damage to multiple organs of the body. For example:

  • Brain damage: mental retardation occurs.
  • Cardiomyopathy: Arrhythmia, myocardial hypertrophy, impaired left ventricular function, and heart failure occur.
  • Hepatomegaly.
  • Pancreatitis.
  • Optic nerve atrophy, etc.

How To Check And Diagnose Whether You Have Propionic Acidemia?

How should propionic acidemia be diagnosed?

  • When the doctor diagnosed the propionic acidemia, he mainly referred to the results of acyl carnitine analysis by blood filter paper tandem mass spectrometry and organic acid analysis by urine gas chromatography-mass spectrometry.
  • The diagnosis could be confirmed if that tandem mas spectrometric results of the patient show an increase in blood propionyl carnitine, propionyl carnitine to free carnitine ratio, propionyl carnitine to acetyl carnitine ratio, glycine level, and the patient's gas chromatography-mass spectrometry results show a large amount of methyl citric acid, 3- hydroxypropionic acid and propionyl glycine in urine.

What tests need to do for propionic acidemia?

General examinations, special biochemical tests and genetic diagnosis are required.

  • General inspection
  1. Routine blood test: to know whether white blood cells, red blood cells and platelets are affected.
  2. Urine routine: find out if you have ketosis.
  3. Blood gas analysis: to understand the existence and severity of metabolic acidosis.
  4. Blood ammonia: judge whether there is hyperammonemia.
  5. Blood lactic acid: learn if you have hyperlipidemia or lactic acidosis.
  6. Blood glucose: understand the situation of blood glucose.
  7. Myocardial enzyme spectrum: to know whether there is myocardial injury.
  • Special biochemical tests: Blood filter paper was used for tandem mass spectrometry analysis of acyl carnitine, and urine was collected for gas chromatography-mass spectrometry analysis of organic acids, which was mainly used to determine the diagnosis.
  • Gene diagnosis: loci where a gene mutation or defect is found can further aid in the diagnosis.


How To Prevent Propionic Acidemia?

Can propionic acidemia be prevented? How to prevent propionic acidemia?

  • The prenatal diagnosis can be directly performed by measuring the enzyme activity and mutant gene of cultured amniotic fluid cells or chorionic tissue, or the level of methyl citric acid in amniotic fluid, to diagnose the diseased fetus, terminate the pregnancy, and avoid the birth of the child.

How to prevent the patient with propionic acidemia to appear undesirable consequence?

  • The possibility of this disease should be considered in unexplained infants with recurrent vomiting, convulsions, uncorrectable acidosis, coma, and developmental delay, especially in infants with a similar family history. Early diagnosis and treatment through related examinations can minimize the complications.

How To Treat Propionic Acidemia?

What department should propionic acidemia go to see a doctor?

  • Neonatal or pediatric.

Can propionic acidemia heal itself?

  • No, it needs lifelong treatment.

How to treat propionic acidemia?

The treatment methods of propionic acidemia mainly include diet therapy, medication and surgery.

  • Diet Therapy

The principle of dietary treatment is to limit the intake of natural protein for a long time, but also to ensure that enough protein and energy.

The protein deficit was replaced with formula milk or protein that free of valine, isoleucine, threonine, and methionine, while avoiding starvation to inhibit muscle and adipose tissue metabolism.

  • Medication

Medication includes L-carnitine, neomycin, metronidazole, carbamoyl glutamic acid, etc.

  1. L-carnitine: it can be combined with acidic substances in the body to promote the metabolism and discharge of acidic substances, so it can be used for the treatment of propionic acidemia. Intravenous drip treatment in the acute phase and oral treatment in the stable phase may cause mild diarrhea and other adverse reactions in some children.
  2. Neomycin or metronidazole: part of propionic acid in the body is produced by the metabolism of intestinal bacteria, and neomycin or metronidazole can inhibit the production of propionic acid by intestinal bacteria, so it can be used for the treatment of propionic acidemia. It is recommended to be used in the acute phase and not for a long time to avoid causing imbalance of intestinal flora.
  3. Carbamoyl glutamic acid: it can improve the metabolism of children, especially in the acute decompensated period, when it has the effect of detoxicating high blood ammonia, thus avoiding further dialysis treatment.
  • Surgical Treatment

In some cases, the symptoms can be markedly improved after liver transplantation, and dietary restrictions and other medical treatments are no longer required, so the disease can be well controlled.

Can propionic acidemia heal?

  • At present, propionic acidemia still lacks specific treatment, and cannot be radically treated.

What Should Propionic Acidemia Patient Notice In Life?

Patients with propionibacteria need to limit the intake of natural protein for a long period of time in the diet, while ensuring adequate protein and energy to meet the needs of growth, development and life.

Children in infancy for every kg body weight need to add 2.5 ~ 3.5 grams of protein per day, childhood for every kg body weight need to add 30 ~ 40 grams of protein per day, adulthood for every kg body weight need to add 50 ~ 65 grams of protein per day.

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