Sitosterolemia: A Case Report and a Concise Literature Review

Area of Science:

• Biochemistry
• Genetics
• Metabolic Disorders

Background:

• Sitosterolemia is a rare lipid metabolism disorder characterized by excessive dietary phytosterol absorption and tissue deposition.
• Mutations in the ABCG5 and ABCG8 genes are implicated in the pathophysiology of sitosterolemia.
• This condition is exceptionally rare, with limited documented cases globally and particularly in the Middle East.

Observation:

• A case presentation of an adult patient from Saudi Arabia with dyslipidemia unresponsive to statin therapy.
• The patient exhibited symptoms consistent with a lipid metabolism disorder.
• Initial treatment with statins did not yield the desired therapeutic effect.

Findings:

• Genetic testing revealed mutations in ABCG5 and ABCG8 genes, confirming a diagnosis of sitosterolemia.
• High levels of phytosterols were detected, indicative of the disorder.
• Treatment with ezetimibe led to significant improvements in the patient's cholesterol levels.

Implications:

• Highlights the importance of genetic testing for diagnosing rare lipid disorders like sitosterolemia, especially in cases of statin resistance.
• Demonstrates the efficacy of ezetimibe in managing hypercholesterolemia associated with sitosterolemia.
• Contributes to the understanding of sitosterolemia prevalence and clinical presentation in the Middle Eastern population.