BACKGROUND: Cerebral venous sinus thrombosis (CVST) is typically associated with a prothrombotic state of the blood, with its causative factors varying widely. Prior research has not reported the simultaneous occurrence of CVST and dural arteriovenous fistulas (DAVFs) as potentially resulting from genetic mutations. In this case report, we introduce a unique occurrence wherein a patient with a heterozygous mutation of the low-density lipoprotein receptor (LDLR) gene presented with CVST in conjunction with DAVFs.
METHODS: Presentation: A male patient, aged 51, sought treatment at our facility due to a consistent decline in cognitive functions accompanied by recurrent headaches. Comprehensive evaluations were administered, including neurological examinations, laboratory tests, magnetic resonance imaging, digital subtraction angiography, and whole exome sequencing. Digital subtraction angiography identified DAVFs in the patient\'s right sigmoid sinus and an occlusion within the left transverse sinus. The whole exome sequencing of blood samples pinpointed a heterozygous mutation in the LDLR gene (NM_000527:exon12:c.C1747T:p.H583Y). Following the confirmed diagnosis of CVST and DAVFs, the patient underwent anticoagulant therapy combined with endovascular procedures - these comprised embolization of the arteriovenous fistula in the right sigmoid sinus and balloon dilation with stent implantation in the left transverse sinus. A six-month follow-up indicated a significant abatement in the patient\'s symptoms.
CONCLUSIONS: This report marks the first documented case of an LDLR gene mutation that could be associated with the onset of CVST and DAVFs. The mutation in the LDLR gene might foster a prothrombotic environment, facilitating the gradual emergence of CVST and the subsequent genesis of DAVFs.

Background: Homozygous familial hypercholesterolemia (HoFH) is a rare and devastating genetic condition characterized by extremely elevated levels of low-density lipoprotein cholesterol (LDL-C) leading to an increased risk of premature atherosclerosis. Patients with Homozygous familial hypercholesterolemia mostly present with mutations in LDLR; however, herein, we present two cases with concomitant microsomal triglyceride transfer protein mutations, who showed different clinical courses and treatment adherence on long-term therapy with the new MTTP inhibitor lomitapide. Objectives: We aimed to present the possibility of preventing the progression of atherosclerotic burden with effective and safe LDL-C reduction in patients with Homozygous familial hypercholesterolemia on low-dose lomitapide therapy and emphasize the role of treatment adherence in therapy success. Methods: We present two patients with phenotypically Homozygous familial hypercholesterolemia, a compound heterozygous woman and a simple homozygous man, both with LDLR and additional MTTP mutations, who were treated with the MTTP-inhibiting agent lomitapide, with different treatment compliances. The role of impulsivity was investigated through Barratt Impulsivity Scale 11, and the extent of the atherosclerotic burden was followed up using coronary artery calcium scoring, echocardiographic and sonographic findings, and, eventually, through a strict follow-up of laboratory parameters. The patients were on lomitapide for 8 and 5 years, respectively, with no adverse effects. Conclusion: When accompanied by good adherence to therapy, low-dose lomitapide on top of standard lipid-lowering therapy with decreased frequency of lipid apheresis prevented the progression of atherosclerotic burden. Non-compliance might occur due to patient impulsivity and non-adherence to a low-fat diet.