LNSLNS

Lavall and colleagues, in their review article on aneurysms of the ascending aorta (1), point out the importance of distinguishing the genotypes for the purposes of differential diagnosis of Loeys-Dietz syndrome type 2 and vascular Ehlers-Danlos syndrome, as this affects the prognosis and determines the further management. We wish to add the following: distinguishing between the phenotypes of Marfan syndrome and Loeys-Dietz syndrome is sometimes not possible, especially when the disease is first diagnosed and in adult patients.

We recently conducted a systematic study (2) in which we confirmed and quantified earlier observations of our own (3) and those of other authors (for example [4]). In 7 of 124 patients who, according to their clinical criteria, had Marfan syndrome, genetic investigations actually yielded a diagnosis of Loeys-Dietz syndrome. This is of utmost importance for the management of these patients, since—as Lavall et al point out—in patients with Loeys-Dietz syndrome, an indication for elective aortic surgery can be defined from a diameter of 40 mm or greater, not of 45 mm or 50 mm, such as in classic Marfan syndrome. Furthermore, genetically determined aortic aneurysms may occur even without or with very mild stigmata of a syndromal disorder and may still be caused by mutations in the FBN1-, TGFBR1-, or TGFBR2-gene. We therefore think that genotype diagnosis is generally indicated in suspected cases of genetically determined aortic aneurysms.

DOI: 10.3238/arztebl.2012.0504b

Prof. Dr. med. Jörg Schmidtke

Institut für Humangenetik, Medizinische Hochschule Hannover

Schmidtke.Joerg@mh-hannover.de

Prof. Dr. med. Yskert von Kodolitsch

Universitäres Herzzentrum Hamburg

kodolitsch@uke.de

Conflict of interest statement

Professor von Kodolitsch has been reimbursed delegate fees for a further medical educational event from a geneticist in private practice.

Professor Schmidtke declares that no conflict of interest exists .

1.
Lavall D, Schäfers HJ, Böhm M, Laufs U: Aneurysms of the ascending aorta. Dtsch Arztebl Int 2012; 109(13): 227–33.
2.
Sheikhzadeh S, Kade C, Keyser B, et al.: Analysis of phenotype and genotype information for the diagnosis of Marfan syndrome. Clin Genet 2011; [Epub ahead of print].
3.
Singh KK, Rommel K, Mishra A, et al.: TGFBR1 and TGFBR2 mutations in patients with features of Marfan syndrome and Loeys-Dietz syndrome. Hum Mutat 2006; 27: 770–7.
4.
Mizuguchi T, Collod-Beroud G, Akiyama T, et al.: Heterozygous TGFBR2 mutations in Marfan syndrome. Nat Genet 2004; 36: 855–60.
1. Lavall D, Schäfers HJ, Böhm M, Laufs U: Aneurysms of the ascending aorta. Dtsch Arztebl Int 2012; 109(13): 227–33.
2.Sheikhzadeh S, Kade C, Keyser B, et al.: Analysis of phenotype and genotype information for the diagnosis of Marfan syndrome. Clin Genet 2011; [Epub ahead of print].
3. Singh KK, Rommel K, Mishra A, et al.: TGFBR1 and TGFBR2 mutations in patients with features of Marfan syndrome and Loeys-Dietz syndrome. Hum Mutat 2006; 27: 770–7.
4. Mizuguchi T, Collod-Beroud G, Akiyama T, et al.: Heterozygous TGFBR2 mutations in Marfan syndrome. Nat Genet 2004; 36: 855–60.