CASE 10528 Published on 06.01.2013

A case of Loeys-Dietz syndrome

Section

Cardiovascular

Case Type

Clinical Cases

Authors

Sperandio M, Bindi A, Funel V, Liberto V, Simonetti G

Policlinico Tor Vergata,
Viale Oxford 81,
00133 Roma (RM), Italy
Patient

24 years, male

Categories
Area of Interest Cardiovascular system, Musculoskeletal spine ; Imaging Technique CT-Angiography, CT
Clinical History
A 24-year-old man was referred to our Institution with the suspicion of Marfan syndrome; he had previously undergone cardiovascular examination and a mechanic aortic valve was implanted.
On admission he showed hypertelorism, “pectus carinatum” and scoliosis; no other phenotypic alterations were observed. Familiar history did not show Marfan-like disorders.
Imaging Findings
A low-dose whole body Contrast-Enhanced CT examination was performed with multiplanar and tridimensional reconstructions.
We observed several major vessel abnormalities:
- Dilatation of the aortic root (45 mm), ascending aorta (43 mm), aortic arch (49 mm) and epiaortic vessels;
- Bovine arch;
- Dilatation of the descending aorta (43 mm) with severe tortuosity;
- Multiple dilatations of the abdominal aorta (maximum diameter 51 x 47 mm), twisted along its major axis;
- Left origin of the right renal artery above the left one, which presented a course posterior to the abdominal aorta;
- Abnormal origin of the superior mesenteric artery, with dilatation on its III proximal (23 mm), and of the coeliac trunk.
Moreover we observed an aneurismatic dilatation of the cardiac apex and left ventricular hypertrophy, we found a Tarlov sacral cyst and confirmed the presence of scoliosis and pectus carinatum.
Molecular genetic testing for syndromic forms of aortic aneurysms was performed and a mutation of TGFBR2 was found.
Discussion
LDS is a rare autosomal dominant connective-tissue disorder characterised by a variety of medical features in the musculoskeletal, skin and cardiovascular systems. The actual prevalence is unknown, but at least 200 families affected have been identified.
The only two mutations known to be associated with LDS are the transforming growth factor beta receptor type I (TGFBR1) and type 2 (TGFBR2) [1, 2, 3]. These mutations cause increment of the downstream TGFB signalling in the connective tissues and subsequent overproduction of collagen, disarrayed elastic fibre and loss of elastin content in the extracellular matrix, with accumulation of amorphous matrix [1-4].
LDS manifests with aggressive vascular pathology: multiple arterial aneurysms and tortuosity are typical and can be observed throughout the course of the head and neck vessels, of the aorta and of all its side branches.
The association of craniofacial or cutaneous findings identifies two subtypes of this syndrome. LDS type I is the most frequent (75% of affected individuals) and is characterised by the presence of craniofacial manifestations (ocular hypertelorism, bifid uvula/cleft palate, craniosynostosis) while LDS type II is associated with cutaneous disorders (velvety and translucent skin, easy bruising, dystrophic scarring) and affects approximately 25% of these patients.
LDS type I and II form a clinical continuum since no association between phenotype and genotype has been demonstrated and intrafamilial clinical variability has been observed. This is probably related to variation of genes encoding factors.
LDS is suspected by clinical characteristics; CT or MR imaging are necessary to identify cardiovascular findings, since the onset of dissection and rupture of aneurysms occurs earlier than in Marfan syndrome [5-10] and at a smaller size [3]. The leading cause of death is in fact the dissection of the thoracic aorta, followed by abdominal aortic dissection and intracranial bleeding [1].
Imaging should provide detailed information about the calibre of dilated vessels and their course [7]. CT reconstruction are also essential for the operatory planning, since aneurysm surgical repair is mandatory in asymptomatic patients to prevent dissection and rupture, although there is a moderate (about 5%) risk of complication, like spontaneous rupture of spleen, bowel, uterus and arteries.
Pregnancy is very risky for affected women, either for aortic dissection or rupture and for uterine rupture, and it should be avoided.
The diagnosis is confirmed by sequence analysis of TGFBR1 or TGFBR2 genes.
Imaging plays a key-role in the follow-up of cardiovascular anomalies.
Differential Diagnosis List
The final diagnosis was Loeys-Dietz syndrome type I.
Marfan syndrome
Ehlers-Danlos syndrome
Shprintzen-Goldberd syndrome
Arterial tortuosity syndrome
Familial thoracic aortic aneurysm/dissection syndrome
Final Diagnosis
The final diagnosis was Loeys-Dietz syndrome type I.
Case information
URL: https://www.eurorad.org/case/10528
DOI: 10.1594/EURORAD/CASE.10528
ISSN: 1563-4086