Short chain acyl-CoA dehydrogenase (SCAD) deficiency is a rare autosomal recessive genetic disorder of fatty acid catabolism belonging to a group of diseases known as fatty acid oxidation disorders (FOD). It occurs because of a deficiency of the short-chain acyl-CoA dehydrogenase (SCAD) enzyme.

Although SCAD was initially thought to produce severe problems including progressive muscle weakness, hypotonia, acidemia, developmental delay, and even early death, it is now believed that this disorder is both more common and less severe in many cases than originally thought at the time of its discovery 20 years ago. Since the advent of expanded newborn screening programs using tandem mass spectrometry technology, many more SCAD infants are being detected, most of whom are well and asymptomatic.

When symptoms are present, they are variable, ranging from severe, neonatal acidosis to mild developmental delay with hypotonia.

The symptoms of SCAD deficiency include a lack of energy, poor growth, and developmental delay.

 This condition belongs to a group of disorders known as fatty acid oxidation disorders (FOD). SCAD deficiency is caused by mutations in the ACADS gene. These mutations lead to a shortage (deficiency) of an enzyme known as short-chain acyl-CoA dehydrogenase, which is involved in the breakdown of short-chain fatty acids. When not enough of this enzyme is present, excessive amounts of fatty acids and ammonia accumulate in the body.

Treatment for this condition typically includes a low-fat diet and avoidance of long periods without food (fasting).

Short-chain acyl-CoA dehydrogenase deficiency or SCAD deficiency is a condition in which the body is unable to break down certain fats. SCAD is considered a fatty acid oxidation condition because people affected by the condition are unable to change some of the fats they eat into the energy the body needs to function.

Causes and risk factors
1. Mutations in the ACADS gene cause SCAD deficiency. This gene provides instructions for making an enzyme called short-chain acyl-CoA dehydrogenase, which is required to break down (metabolize) a group of fats called short-chain fatty acids.

2. Fatty acids are a major source of energy for the heart and muscles. During periods of fasting, fatty acids are also an important energy source for the liver and other tissues.

3. Mutations in the ACADS gene lead to a shortage (deficiency) of the SCAD enzyme within cells. Without sufficient amounts of this enzyme, short-chain fatty acids are not metabolized properly.

4. As a result, these fats are not converted into energy, which can lead to the signs and symptoms of this disorder, such as lethargy, hypoglycemia, and muscle weakness. It remains unclear why some people with SCAD deficiency never develop any symptoms.

Inheritance
1. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations.
2. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition

Symptoms
Vomiting,Low blood sugar (hypoglycemia),A lack of energy (lethargy),Poor feeding,Failure to gain weight and grow at the expected rate (failure to thrive)
Conditions
A condition that prevents the body from converting certain fats into energy, especially during periods without food (fasting)
Drugs
L-carnitine supplements

Most individuals with SCAD deficiency never experience symptoms, while some individuals experience serious health effects. Detecting the condition early and beginning treatment may help prevent many of the serious outcomes of the disease.

Dietary Treatment
1. Affected infant may need to be on a restricted diet to avoid foods that contain fats that their body cannot break down. A dietician or nutritionist can help you plan a healthy diet for your baby.
2. Eating often can help avoid many of the signs mentioned in the Early Signs section.

Supplements and Medications
1. Some children with short chain acyl-CoA dehydrogenase deficiency (SCAD) take prescription L-carnitine supplements.
2. L-carnitine is a substance naturally made by the body, but the patient's baby's body might not make enough of it.
3. Taking L-carnitine supplements can help the body break down fats and get rid of harmful substances.
4. The doctor might also prescribe riboflavin (Vitamin B2) supplements

Symptoms
Vomiting,Low blood sugar (hypoglycemia),A lack of energy (lethargy),Poor feeding,Failure to gain weight and grow at the expected rate (failure to thrive)
Conditions
A condition that prevents the body from converting certain fats into energy, especially during periods without food (fasting)
Drugs
L-carnitine supplements