New Marfan syndrome criteria to yield more accurate diagnoses, better medical management

An international panel of experts in the diagnosis and management of Marfan syndrome have developed newly published diagnostic criteria for the connective tissue disorder.

With a multi-system clinical examination at its core, the new diagnostic process evaluates patients using a systemic score, which is expected to simplify the evaluation process for physicians, according to a press release from the Journal of Medical Genetics, which recently published the new criteria.

“The diagnostic evaluation for Marfan syndrome is unavoidably complex due to the highly variable presentation of affected individuals, the age-dependent nature of many of its manifestations, absence of gold standards and its extensive differential diagnosis,” Bart Loeys, MD, of the Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium, who led the panel, stated in the release.

“While diagnostic criteria should emphasize simplicity of use and the desire for early diagnosis, the highest priority in developing these guidelines was accuracy,” he stated.

Systemic, numeric score

The new nosology criteria provide a method for evaluating a patient by deriving a systemic score whereby various features of the syndrome are assigned a numeric value with the definitive diagnosis ultimately based on the total systemic score. Its modifications include heavier weighting of the scores of Marfan syndrome’s two cardinal features — aortic root dilation/dissection and ectopic lentis or dislocated lens of the eye — and a more precise role for molecular testing in the evaluation.

Specific diagnotic guidelines were also included for those with and without a family history of the condition and for children less than 20 years of age.

“These new diagnostic criteria will be of great benefit to both physicians, particularly those who do not see many cases of Marfan syndrome, and patients,” Carolyn Levering, President and CEO of the National Marfan Foundation, in Port Washington, N.Y., stated. “It addresses the practical challenges that diagnosing the condition presents to physicians and, at the same time, protects patients by balancing the use of diagnostic categories with a discussion of ongoing risk and the need for follow-up and management.”

The previous nosology depended greatly on evaluating features as “major” or “minor.”

Funding to develop the revised nosology was from the National Marfan Foundation, March of Dimes, Merck and Solvay Pharma.

Reference:
Loeys BL, Dietz HC, Braverman AC, et al. The revised Ghent nosology for the Marfan Syndrome. J Med Genet. 2010;47:476-485.

The new diagnostic criteria focus on the importance of the cardiac manifestations. They also describe the evolution of features over time in children, so that they are not “ruled out” prematurely. The criteria also place the values of the genetic test for fibrillin mutation in a more modern context. In other words, once the examining physician has a suspicion of Marfan syndrome, specialists can now make the diagnosis more definitively.

— Paul D. Sponseller, MD
Marfan syndrome criteria panelist
Department of Orthopaedic Surgery
Johns Hopkins Medical Institutions, Baltimore