a Marfan syndrome diagnosis is confirmed by the presence of sufficient systemic findings Marfan Foundation Calculation of Systemic Score - Marfan Foundation

To address this discrepancy, the concept of the Z-score—a statistical measure describing a value's relationship to the mean of a group—has become integral to modern diagnostic protocols. This paper explores the methodology of Z-score calculation and its indispensable role in the diagnostic criteria and management of MFS.

There is no single universal formula for calculating the aortic root Z-score, as different regression models have been proposed over the decades. The accuracy of a Z-score depends heavily on the reference population from which the normative data was derived.