Acute Coronary Syndrome Developed in a 17-year-old Boy with Sitosterolemia Comorbid with Takayasu Arteritis: A Rare Case Report and Review of the Literature

Abstract

A 17-year-old boy with acute coronary syndrome was admitted to our hospital. He had xanthomas over his elbow and Achilles tendon and a high level of low-density lipoprotein cholesterol; therefore, his initial diagnosis was familial hypercholesterolemia. However, a genetic analysis revealed a compound heterozygous mutation in the ABCG5 gene with a high serum level of sitosterol, leading to the diagnosis of sitosterolemia. After lipid-lowering treatment, percutaneous coronary intervention was performed. Furthermore, a persistently high C-reactive protein level and images of large arteries led to a diagnosis of Takayasu arteritis. To our knowledge, this is the first case of sitosterolemia complicated by Takayasu arteritis.

Children with Severe Hypercholesterolemia Caused by a Pathogenic Mutation in <i>ABCG5</i>

“…Therefore, a dysfunction caused by genetic mutations will lead to elevated serum sterol levels. Sitosterolemia caused by critical biallelic genetic mutations is a recessive disorder characterized by extremely high LDL cholesterol and sitosterol levels (11)(12)(13)(14)(15)(16)(17)(18). However, there are emerging data showing that a single mutation in ABCG5 can exceed the clinical threshold, and this is referred to as hyper LDL cholesterolemia.…”

An infant with a heterozygous variant of <i>ABCG5</i> presented with hypercholesterolemia only during breastfeeding

“…Restrictions of cholesterol and plant sterols and administration of ezetimibe, an inhibitor of NPC1L1, are effective in the treatment of patients with sitosterolemia ( 6 , 19 ). In patients with an ABCG5 heterozygous variant, cholesterol levels are expected to improve with dietary therapy alone, as was the case in our patient.…”

A case of sitosterolaemia-caused systemic large-vessel stenosis mimicking Takayasu arteritis in which FDG-PET provided a clue for the differential diagnosis

“…Only one report has described the detection of tendon xanthomas by FDG-PET in a case of familial hypercholesterolaemia, possibly due to the presence of foamy macrophages with high metabolic rates in the tendons [ 7 ]. In addition, there have been reports of cases of sitosterolaemia combined with Takayasu arteritis [ 8 ]; if Takayasu arteritis is active, the FDG accumulation in the large vessels can be confirmed by FDG-PET. Although the frequency of primary dyslipidaemia is much lower than that of LVV, each therapy is different, and misdiagnosis can be life-threatening.…”