Editing Marfan syndrome (section)

===Skeletal system===
Most of the readily visible signs are associated with the [[human skeleton|skeletal system]]. Many people with Marfan syndrome grow to above-average height, and some have [[Dolichostenomelia|disproportionately long, slender limbs]] with thin, weak wrists and [[Arachnodactyly|long fingers and toes]].

The&nbsp;Steinberg sign, also known as the&nbsp;thumb sign, is one of the clinical examination tests for&nbsp;Marfan disease&nbsp;in the hands. It is a clinical test in which the tip of the thumb extends beyond the palm when the thumb is clasped in the clenched hand.<ref>{{cite web | url=https://www.scmp.com/lifestyle/health/article/1368777/lifelong-drug-therapy-key-coping-marfan-syndrome | title=Lifelong drug therapy the key to coping with Marfan syndrome | newspaper=[[South China Morning Post]] | date=2 December 2013 | access-date=18 February 2022 | archive-date=18 February 2022 | archive-url=https://web.archive.org/web/20220218190133/https://www.scmp.com/lifestyle/health/article/1368777/lifelong-drug-therapy-key-coping-marfan-syndrome | url-status=live }}</ref><ref>{{cite journal
 | url=https://academic.oup.com/qjmed/article/108/6/509/1547885
 | title=Marfan syndrome and the thumb sign
 | journal=[[QJM]]
 | volume=108
 | issue=6
 | page=509
 | date=19 November 2014
 | pmid=25411342
 | last1=Zoabi
 | first1=A.
 | last2=Lavie
 | first2=G.
 | doi=10.1093/qjmed/hcu224
 | doi-access=free
 | access-date=18 February 2022
 | archive-date=18 February 2022
 | archive-url=https://web.archive.org/web/20220218190712/https://academic.oup.com/qjmed/article/108/6/509/1547885
 | url-status=live
 }}</ref><ref>{{cite web| url = https://radiopaedia.org/articles/steinberg-sign-marfan-disease| title = Steinberg sign (Marfan disease)| website = [[Radiopaedia]]| date = 26 December 2016| access-date = 2021-10-17| archive-date = 2021-10-17| archive-url = https://web.archive.org/web/20211017055618/https://radiopaedia.org/articles/steinberg-sign-marfan-disease| url-status = live}}</ref>

Besides affecting height and limb proportions, people with Marfan syndrome may have abnormal lateral curvature of the spine [[scoliosis]], thoracic [[lordosis]], abnormal indentation (''[[pectus excavatum]]'') or protrusion (''[[pectus carinatum]]'') of the [[sternum]], [[hypermobility (joints)|abnormal joint flexibility]], a [[high-arched palate]] with crowded teeth and an overbite, [[flat feet]], [[hammer toe]]s, stooped shoulders, and unexplained [[stretch marks]] on the skin. It can also cause pain in the joints, bones, and muscles. Some people with Marfan have [[speech disorder]]s resulting from symptomatic high palates and small jaws. Early [[osteoarthritis]] may occur. Other signs include limited range of motion in the hips due to the [[femoral head]] protruding into [[protrusio acetabuli|abnormally deep hip sockets]].<ref name="Van de Velde 2006">{{cite journal | vauthors = Van de Velde S, Fillman R, Yandow S | title = Protrusio acetabuli in Marfan syndrome. History, diagnosis, and treatment | journal = The Journal of Bone and Joint Surgery. American Volume | volume = 88 | issue = 3 | pages = 639–646 | date = March 2006 | pmid = 16510833 | doi = 10.2106/JBJS.E.00567 | doi-broken-date = 18 March 2025 }}</ref><ref name=":1" />