Expanding the clinical spectrum of biglycan-related Meester-Loeys syndrome

Pathogenic loss-of-function variants in BGN, an X-linked gene encoding biglycan, are associated with Meester-Loeys syndrome (MRLS), a thoracic aortic aneurysm/dissection syndrome. Since the initial publication of five probands in 2017, we have considerably expanded our MRLS cohort to a total of 18 probands (16 males and 2 females). Segregation analyses identified 36 additional BGN variant-harboring family members (9 males and 27 females). The identified BGN variants were shown to lead to loss-of-function by cDNA and Western Blot analyses of skin fibroblasts or were strongly predicted to lead to loss-of-function based on the nature of the variant. No (likely) pathogenic missense variants without additional (predicted) splice effects were identified. Interestingly, a male proband with a deletion spanning the coding sequence of BGN and the 5' untranslated region of the downstream gene (ATP2B3) presented with a more severe skeletal phenotype. This may possibly be explained by expressional activation of the downstream ATPase ATP2B3 (normally repressed in skin fibroblasts) driven by the remnant BGN promotor. This study highlights that aneurysms and dissections in MRLS extend beyond the thoracic aorta, affecting the entire arterial tree, and cardiovascular symptoms may coincide with non-specific connective tissue features. Furthermore, the clinical presentation is more severe and penetrant in males compared to females. Extensive analysis at RNA, cDNA, and/or protein level is recommended to prove a loss-of-function effect before determining the pathogenicity of identified BGN missense and non-canonical splice variants. In conclusion, distinct mechanisms may underlie the wide phenotypic spectrum of MRLS patients carrying loss-of-function variants in BGN.

Inferior vena caval filter strut perforation causing intramural duodenal haematoma

We present a case of intramural duodenal haematoma caused by inferior vena caval (IVC) filter strut perforation requiring innovative open and endovascular retrieval. A 32-year-old woman presents in shock with dull epigastric pain and non-bilious vomiting. She had previously had an IVC filter for deep venous thrombosis and pulmonary embolism. Computed tomography demonstrated strut perforation into the second part of the duodenum, causing intramural haematoma and duodenal obstruction. Laparotomy facilitated evacuation of the duodenal haematoma, while the IVC filter was retrieved by endovascular means. Causes of duodenal haematoma include blunt trauma, haematologic malignancy, coagulopathy, percutaneous or endoscopic procedures, pancreatic pathology, peptic ulcer disease and aortoenteric fistula. Duodenal haematoma is rare and is usually managed conservatively or by percutaneous drainage. While this patient had a typical presentation, IVC filter strut perforation has not been described in the literature as a cause for duodenal haematoma.

Aortitis causing rapid growth of a mycotic aortic aneurysm

Mycotic infrarenal aortic aneurysms are rare and often masquerade as other abdominal pathology. We present a case where serial imaging made the diagnosis and provided an insight into the pathophysiology of mycotic aneurysm. A 71-year-old man presents with abdominal pain, rigours and dysuria. Computed tomography reveals an irregular, thickened ectatic abdominal aorta, but cholescintigraphy suggests acalculous cholecystitis. Deterioration prompts repeat radiographical assessment, which demonstrates an increase in the size of the aorta over 10 days. The patient was treated emergently with an open aortic ligation, debridement and extra-anatomical bypass. Infections account for up to 2% of abdominal aortic aneurysms. The rate of growth of mycotic aneurysms is sparsely discussed in the literature and to our knowledge, there are no reports with serial single-modality imaging. The most significant finding was rapid expansion in aneurysm size. While mycotic aneurysm requires urgent treatment, diagnosis can be delayed and difficult.