SNP Shot: Genomic Insights

Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency is a rare disorder that impairs the body's ability to use certain fats for energy, especially when food intake is limited (fasting).

Symptoms of LCHAD deficiency usually manifest in infancy or early childhood. Many affected babies struggle with feeding, displaying strong aversions to specific foods or eating in general, along with nausea and vomiting. Other symptoms can include extreme tiredness (lethargy), low blood sugar (hypoglycemia), poor muscle tone (hypotonia), developmental delays, liver complications, and abnormalities in the retina, the light-sensitive tissue at the back of the eye. These retinal issues can lead to impaired vision, nearsightedness (myopia), or difficulty seeing in dim light (night blindness), and these vision problems tend to worsen over time. As children get older, they may experience muscle pain, muscle breakdown (rhabdomyolysis), and nerve damage causing numbness or weakness in the arms and legs (peripheral neuropathy). Infants and children with LCHAD deficiency are also at increased risk for serious heart problems, including a weakened heart muscle (cardiomyopathy) and heart failure, as well as breathing problems, coma, and sudden death.

LCHAD deficiency-related problems can be triggered by bodily stresses, such as fasting, illnesses like viral infections, or extreme temperatures. This condition can be confused with Reye syndrome, a serious illness that can occur in children recovering from viral infections like chickenpox or the flu. Aspirin use during these infections is often linked to Reye syndrome.

Inheritance:

LCHAD deficiency follows an autosomal recessive inheritance pattern. This means that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition. Parents of children with autosomal recessive conditions each carry one copy of the mutated gene but usually do not exhibit any symptoms themselves.