Young: Medical Genetics 
Multiple Choice QuestionsYoung: Medical Genetics
Chapter 1
Ivar the Boneless (approx 794 – 872)
Ivar the Boneless was almost certainly a genuine historical figure, but the truth of the sagas relating his military conquests and physical disability will probably never be known. Legend holds that the bones in his lower limbs were so poorly formed that he was unable to walk. However, his upper limbs were extremely powerful and his intellect outstanding. Through strength of personality he became a Viking chieftain and went on to lead a successful invasion of eastern England in 865AD. Again according to legend, he was carried by his warriors on a large shield from which he was able to fire heavy arrows at his unfortunate foes using his unique upper body strength. Having captured Jorvik (York) in 866, he sensibly retired to the relative tranquillity of life in Dublin, then a small settlement in Ireland that had been founded by the Vikings several years previously.
Medical scholars of the Viking legends have proposed that Ivar might have had a severe form of osteogenesis imperfecta (OI). This relatively common condition, widely known as brittle bone disease, can be classified into three main forms. In type I, the most common, bone fragility is mild and affected individuals lead relatively normal lives with minimal disability. The ocular sclerae are blue, because of the transparency caused by collagen depletion, and deafness often develops in middle age primarily because of middle ear disease. In type II, bone fragility is extreme and death usually occurs before or soon after birth. Type III, which could have accounted for Ivar’s disability, manifests with relatively severe fragility leading to bowing and progressive deformity, particularly in the lower limbs. The basic defect in almost all cases lies in collagen, with a well established functional relationship between the type of mutation and the clinical outcome. This is explained further on page 14.
There are many possible explanations for weakness in the lower limbs such as arthrogryposis, ‘cerebral palsy’, congenital myopathy and bone malformations, and there is no firm information to support a diagnosis of OI or any other specific condition in Ivar. Cynics have even proposed that his epithet may have been a reference to erectile dysfunction and cite an assertion that ‘he had no love lust in him’. History records that William the Conqueror disinterred Ivar’s remains and burned them so that it is extremely unlikely that the true explanation for his disability will ever be established.
Reference
Editorial (1957) Ivar the Boneless. British Medical Journal,1, 1172-1173.
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