Fatty Acid Metabolism Disorders in Infants: A Genetic Syndrome If diagnosed and treated early, most infants with this condition can live healthy, normal lives. However, if left untreated, children may face severe health issues, potentially leading to death.
1. Overview of Metabolic Disorders in Infants
Typically, there are three main components in everyone’s diet: protein, lipids, and carbohydrates. Once ingested, these components are metabolized to produce energy, which is essential for survival and development. The metabolism of these components requires various enzymes, receptors, transport proteins, and co-factors, all of which are synthesized under the control of corresponding genes, thus representing an individual’s unique genetic makeup.
Metabolic disorders in infants are one of the rare congenital diseases, caused by a deficiency of receptors, transport proteins, enzymes, and co-factors involved in the metabolism of fatty acids, amino acids, and organic acids. This leads to alterations in the synthesis or breakdown pathways of substances within the body, resulting in abnormal products that can cause cellular toxicity and impair the function of several organs in the child.
This condition can be classified into three main groups:
- Amino acid metabolism disorders in infants;
- Fatty acid metabolism disorders in infants;
- Carbohydrate metabolism disorders in infants.
When experiencing metabolic disorders, infants may exhibit symptoms such as lethargy, refusal to feed, vomiting, fever, declining health, abdominal distension, diarrhea, unusual odors in urine and sweat, rapid breathing or apnea despite no history of birth asphyxia, arrhythmia, potential coma, seizures, or even death.
Fever is a common symptom in infants with fatty acid metabolism disorders
2. What are Fatty Acid Metabolism Disorders in Infants?
2.1 Definition
This is a congenital syndrome that affects an infant’s ability to metabolize fats. In healthy infants, the body utilizes glucose from starches and sugars to generate energy for vital activities. When glucose reserves are depleted, the body mobilizes stored energy from fats. However, infants with fatty acid metabolism syndrome cannot utilize fats for energy production, leading to persistently low blood sugar levels and an accumulation of harmful substances in their blood.
2.2 Symptoms
Fatty acid metabolism disorders are hereditary syndromes that typically manifest in young children, although they may rarely occur in adults. Symptoms may be triggered by infections, food poisoning, illness, or other infections, and can include: drowsiness, fever, irritability, behavioral changes, nausea and vomiting, diarrhea, reduced appetite, loss of sensation in the arms and legs, muscle pain, cramps, overall weakness, low blood sugar levels, and vision impairment.
2.3 Complications
If diagnosed and treated early, most children with fatty acid metabolism disorders can lead healthy, normal lives. However, if left untreated, this condition can lead to serious health issues such as anemia, breathing difficulties, brain damage, coma, damage to the heart, liver, lungs, cognitive and developmental delays, seizures, epilepsy, and even death.
One of the dangerous complications of fatty acid metabolism disorders is seizures.
2.4 Screening Tests for Fatty Acid Metabolism Disorders in Infants
Experts recommend that all infants undergo screening tests for fatty acid metabolism disorders to prevent the risk of unwanted complications. Common tests include:
- Carnitine absorption deficiency test: Carnitine is essential for the body to convert fats into energy. Individuals with this deficiency cannot utilize Carnitine for this function. Symptoms may appear from birth up to seven years of age, but some children may show no abnormal signs;
- Long-chain hydroxyacyl-CoA dehydrogenase deficiency test: Symptoms typically manifest within the first year of life;
- Very long-chain acyl-CoA dehydrogenase deficiency test: This condition can present in three types, occurring before four months, around one year, or in adulthood;
- Medium-chain acyl-CoA dehydrogenase deficiency test: Symptoms are primarily observed in young children and rarely emerge in adulthood;
- Deficiency of three functional proteins: This condition has three forms: early stage (symptoms appear within the first two years), childhood stage (symptoms usually appear after the child is one year old), and mild form (rarely, symptoms manifest after two years of age).
Screening tests for fatty acid metabolism disorders help prevent potential complications
2.5 Prevention and Treatment
Prevention
- Avoid consanguineous marriages;
- Pre-marital health examinations and genetic counseling;
- During pregnancy, prenatal screening through ultrasound, and newborn screening after birth;
- In cases such as mothers who repeatedly have stillbirths, children diagnosed with congenital metabolic disorders, or parents carrying genetic disorders in the family, it is essential to inform healthcare providers to ensure early care and conduct newborn screening for infants at birth.
The above measures aid in the early diagnosis and treatment of abnormal issues in infants, reducing the neonatal mortality rate.
Treatment
Currently, there is no definitive treatment for metabolic disorders in children in general, and fatty acid metabolism disorders in particular. Treatment approaches focus on mitigating the symptoms of the condition. Some treatment methods for children include:
- Establishing an appropriate diet, avoiding foods that the child cannot metabolize. Infants require specially formulated milk, while older children need strict dietary control;
- Supplementing essential vitamins and minerals to boost immunity and enhance metabolic capacity. For fatty acids that cannot be metabolized, supplementation should be in a form that the child can absorb;
- Regular health monitoring to ensure that body indicators remain stable;
- Some newer treatment methods: stem cell and bone marrow transplants.
Parents should regularly take children for routine health check-ups.
Fatty acid metabolism disorders in infants can lead to many dangerous complications. Therefore, early screening is necessary to identify, diagnose, and treat promptly, reducing mortality rates and the risk of disabilities in children.
