PHN coefficients are verbatim from Lopez 2017 Table 2 (PMC5812349); α is 0.50 for all four sites. The tests match ParameterZ’s PHN calculator to 10−6 for three patients. PHN population: healthy, non-obese, term children aged 18 years or younger. Detroit coefficients were reconstructed from ParameterZ’s Pettersen calculator because the paper’s table could not be retrieved, so they are [unverified]; see the Echo Z-Scores page for details. Detroit is not shown above BSA 2.0 m² and has no ascending aorta equation.
Revised Ghent nosology (Loeys 2010)
Read in full: rules from Box 1, the systemic score from Box 2, the children’s terms and measurement advice from the text. The Marfan Foundation’s rules page (marfan.org/dx/rules) and GeneReviews (Dietz, NBK1335) give the same rules and points. Loeys 2010 is an expert-panel consensus.
Without family history: (1) aortic root Z ≥ 2 and ectopia lentis*; (2) Z ≥ 2 and a bona fide FBN1 variant; (3) Z ≥ 2 and systemic score ≥ 7*; (4) ectopia lentis and an FBN1 variant previously associated with aortic root aneurysm or dissection.
With family history (a relative independently diagnosed by these criteria): (5) ectopia lentis; (6) systemic score ≥ 7*; (7) aortic root Z ≥ 2 at 20 years or older, ≥ 3 under 20*. The text says “≥ 20 years”, Box 1 “above 20”; this page treats exactly 20 years as 20 or older, as the text does.
“Aortic root” means the diameter at the sinuses of Valsalva at the stated Z, or an aortic root dissection (Box 1); the dissection box counts for rules 1, 2, 3 and 7. The text’s family-history sentence names only dilatation; Box 1 uses the same “Ao”, which includes dissection. Descending aortic aneurysm or dissection without root enlargement is not part of the criteria.
*Only without discriminating features of Shprintzen-Goldberg, Loeys-Dietz or vascular Ehlers-Danlos syndrome, and after TGFBR1/2, collagen biochemistry and COL3A1 testing when indicated; Loeys 2010 adds that other conditions and genes will emerge. Loeys-Dietz syndrome is now also linked to SMAD3, TGFB2 and TGFB3 (2022 ACC/AHA aortic disease guideline) and SMAD2 (ESC 2024; AHA 2024 pediatric aortopathy statement).
FBN1: Loeys 2010 says “mutation”; Box 3 counts one previously shown to segregate in a Marfan family; a de novo mutation (with proven paternity and absence of disease in the parents) that is nonsense, deletion/insertion, at a canonical splice site or shown to alter splicing at mRNA/cDNA level, or a cysteine or EGF calcium-binding missense; another missense that segregates in the family if possible, and is absent in 400 ethnically matched control chromosomes (absence in controls alone when there is no family history); or linkage over at least 6 meioses. This page uses today’s term, pathogenic variant.
Under 20 years: “non-specific connective tissue disorder” for a sporadic case without an FBN1 variant whose systemic score is below 7 and/or aortic root Z is borderline (below 3), until follow-up shows Z 3 or more; “potential Marfan syndrome” for a sporadic or familial case with an FBN1 variant and an aortic root still below Z 3. Loeys 2010 offers these terms for children who do not fit the four scenarios, but its Z 3 bound for “potential Marfan syndrome” overlaps rule 2 (Z ≥ 2 with FBN1); this page lists rule 2 when it is met and shows the term only when no rule is met.
Systemic score (Box 2; maximum 20; ≥ 7 is positive): wrist AND thumb sign 3 (wrist OR thumb 1); pectus carinatum 2 (pectus excavatum or chest asymmetry 1); hindfoot deformity 2 (plain flat foot 1); pneumothorax 2; dural ectasia 2; protrusio acetabuli 2; reduced US/LS with increased arm span/height and no severe scoliosis 1; scoliosis or thoracolumbar kyphosis 1; reduced elbow extension 1; 3 of 5 facial features 1; skin striae 1; myopia above 3 diopters 1 (Box 2 says > 3; one sentence of the text says ≥ 3); mitral valve prolapse 1.
Which Z score. Loeys 2010 does not fix one nomogram: it says the Z score is valid only if the root is measured the way the normal data were. For inner edge to inner edge in systole up to 25 years it points to the Marfan Foundation’s calculator; for leading edge to leading edge in diastole at any age, to Roman 1989. Both predate PHN (Lopez 2017), which the paper does not mention; using PHN Z for the Ghent thresholds is this page’s choice. The page lists which rules the entries satisfy; it does not make a diagnosis, and the alternative diagnoses (ectopia lentis syndrome, MASS phenotype, MVP syndrome, Loeys-Dietz and others) need clinical and genetic evaluation.
Verification
Checked in October 2026: PHN Z scores for the annulus, sinuses, sinotubular junction and ascending aorta agree with the official PHN calculator in 24 of 24 values when it is given the same BSA (17 of 24 at two decimals against its displayed values, which round BSA first). The systemic score agrees with The Marfan Foundation’s scoring in all 6 tested combinations (0 to 20 points) and with Loeys 2010 Box 2; the Ghent rules agree with the Foundation’s rule text in 14 of 14 cases and with Loeys 2010 Box 1 in every tested case, including aortic root dissection. Reference population: the Marfan Foundation’s children’s aortic root calculator uses a different reference (its formula is a Boston/Colan-type model) and gives a lower Z for the same root: PHN Z 2 is about 1.3 to 1.5 there, PHN Z 3 about 2.0 to 2.4. So PHN Z reaches the Ghent Z ≥ 2 and Z ≥ 3 thresholds at a smaller root than the Foundation’s calculator does: about 1 to 1.5 mm smaller in a school-age child, and about 2 to 3 mm at adolescent or adult size (BSA 2.1 m²).
Lopez L, et al. Pediatric Heart Network echocardiographic Z scores: comparison to other published models. J Am Soc Echocardiogr 2021;34(2):185-192. doi:10.1016/j.echo.2020.09.019
Loeys BL, Dietz HC, Braverman AC, et al. The revised Ghent nosology for the Marfan syndrome. J Med Genet 2010;47(7):476-485. doi:10.1136/jmg.2009.072785
Roman MJ, Devereux RB, Kramer-Fox R, O’Loughlin J. Two-dimensional echocardiographic aortic root dimensions in normal children and adults. Am J Cardiol 1989;64(8):507-512 (the nomogram Loeys 2010 cites for leading-edge, diastolic measurements; not implemented here). doi:10.1016/0002-9149(89)90430-X
Isselbacher EM, Preventza O, Hamilton Black J 3rd, et al. 2022 ACC/AHA guideline for the diagnosis and management of aortic disease. Circulation 2022;146(24):e334-e482. doi:10.1161/CIR.0000000000001106
Mazzolai L, Teixido-Tura G, Lanzi S, et al. 2024 ESC Guidelines for the management of peripheral arterial and aortic diseases. Eur Heart J 2024;45(36):3538-3700. doi:10.1093/eurheartj/ehae179
Morris SA, Flyer JN, Yetman AT, et al. Cardiovascular management of aortopathy in children: a scientific statement from the American Heart Association. Circulation 2024;150(11):e228-e254. doi:10.1161/CIR.0000000000001265