Although Loeys-Dietz syndrome shows overlap with other disorders such as Marfan Syndrome (MFS), Ehlers-Danlos Syndrome (EDS), Shprintzen-Goldberg syndrome (SGS) and others, a variety of differential features set LDS apart from other disorders.
LDS & Marfan syndrome
Individuals diagnosed with Marfan syndrome (MFS) exhibit several findings not found in LDS patients. These include:
ectopia lentis (dislocation of the lens of the eye)
- Note: now seeing some cases of ectopia lentis in LDS patients
- dolichostenomelia (prominently long limbs)
Individuals with LDS tend to have a more translucent quality to their skin, allowing veins to be easily visible. Abnormal scarring and easy bruising also may occur to a greater degree in individuals with LDS.
Birth defects such as clubfoot, other structural heart defects and cleft palate (opening and obvious gap in the roof of the mouth) are also more likely to be associated with LDS.
It has also been discovered that the genetic cause for these two disorders is distinct. MFS is caused by a mutation (gene change) in the fibrillin-1 (FBN1) gene, while LDS is caused by a mutation the TGFBR1, TGFBR2, SMAD3, TGFB2, SMAD2 and TGFB3 gene.
LDS and Ehlers-Danlos syndrome
LDS is similar to vascular type Ehlers-Danlos (EDS) in that skin-related findings such as easy bruising, soft/velvety skin texture, wide scarring and translucent skin are seen in both syndromes. Both LDS and vascular type EDS have a relatively high instance of arterial aneurysms and, to a lesser degree, spontaneous organ rupture. Clubfoot may be observed in both disorders.
The disorders are different in that individuals with LDS have physical findings typically not present in individuals with vascular type EDS, such as widely-spaced eyes and bifid uvula.
Vascular type EDS occurs when the collagen an individual produces is not the appropriate quantity or quality. Genetic testing for a mutation in the COL3a1 gene or collagen biochemical studies performed on a skin biopsy sample can confirm this diagnosis. Individuals exhibiting EDS-like symptoms but who have had a normal test for vascular type EDS should be evaluated for LDS.
LDS and Shprintzen-Goldberg syndrome
Individuals with Shprintzen-Goldberg syndrome (SGS) and LDS may have similar findings, including craniosynostosis, pectus anomalies and scoliosis.
However, the vast majority of individuals with SGS do not show progressive or severe aneurysm formation of the aortic root or of other arteries. Another difference between these two disorders is that individuals with SGS are also more likely to show developmental delay. SGS is caused by mutations in the SKI gene.
LDS & BGN-Associated Aortic Aneurysm Syndrome
The clinical features of BGN-Associated Aortic Aneurysm Syndrome significantly overlap with LDS. These overlapping features include widely spaced eyes, bifid uvula, chest deformities, joint hypermobility and early-onset aortic root dilatation and dissection. This syndrome is caused by a variant in the BGN gene.
Medical information both provisioned by The Loeys-Dietz Syndrome Foundation. © 2019 and retrieved from: Loeys B, Dietz H. The Loeys-Dietz Syndrome. GeneReviews [Internet]. 2018
Last Updated March 27, 2020