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BJD
British Journal of Dermatology

CASE REPORT

Tenascin-X deficiency and Ehlers–Danlos syndrome: a case
report and review of the literature
M. O’Connell, N.P. Burrows,* M.J.J. van Vlijmen-Willems,  S.M. Clark and J. Schalkwijk 
Department of Dermatology, The General Infirmary at Leeds, Great George’s Street, Leeds LS1 3EX, U.K.
*Department of Dermatology, Addenbrooke’s Hospital, HillsRoad, Cambridge CB2 2QQ, U.K.
 Department of Dermatology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands

Summary
Correspondence
Michael O’Connell.
E-mail: Michael.O’Connell@
leedsth.nhs.uk; mickoconnell@
doctors.net.uk

Tenascin-X is a large extracellular matrix glycoprotein that is widely distributed
within connective tissues and is associated with an autosomalrecessive type of
Ehlers–Danlos syndrome (EDS). Tenascin-X represents the first EDS susceptibility
gene that does not code for a fibrillar collagen or collagen-processing enzyme.
We describe a paediatric case of tenascin-X deficiency and review the literature.

Accepted for publication
14 July 2010

Key words
Ehlers–Danlos syndrome, skin hyperextensibility,
tenascin-X deficiency

Conflicts ofinterest
None declared.
DOI 10.1111/j.1365-2133.2010.09949.x

The Ehlers–Danlos syndrome (EDS) phenotype is characterized
by a decrease in the tensile strength and integrity of connective
tissues. It is a genetically heterogeneous disorder, which manifests clinically with the classic triad of skin hyperextensibility,
joint hypermobility and poor wound healing. Pathogenesis
relates largelyto defects in collagen synthesis and metabolism.
The underlying genetic mutations responsible for EDS have
been confined mostly to genes encoding fibrillar proteins or
collagen-processing enzymes. However, mutations giving rise
to tenascin-X deficiency have also been identified in the pathogenesis of EDS. This paper describes EDS due to tenascin-X
deficiency in a 7-year-old boy, which wasinitially presented at
the British Society for Paediatric Dermatology meeting1 and to
our knowledge is the first case reported from the U.K.

Case report
The patient was initially referred at age 7 years through the
paediatric department with a history of slightly elastic skin. On
enquiry, the patient was noted to have had a soft skin texture
from the age of 2 years. A bruising diathesis wasreported but
no scarring was identified. Some joint hypermobility was also
reported but no history of dislocations or fractures was elicited.
Similarly, no cardiovascular, respiratory or ophthalmic sequelae
were noted. The patient was the second child of a consanguin-

eous relationship. The family history was unremarkable dating
back two generations. The mother had a slightly increased carryingangle of the elbows but no other features of joint hypermobility were noted. An obstetric history was unremarkable.
The older sibling was not reported to demonstrate any of the
cutaneous or joint problems identified in the patient. On examination, the patient demonstrated skin hyperextensibility in
association with a soft and dough-like texture (Fig. 1). A cutaneous examination of the lowerlimbs identified marked pes
planus and the presence of multiple piezogenic pedal papules
(Fig. 2). No scarring was apparent (Fig. 3). Mild joint hypermobility was elicited and a slightly increased carrying angle at
the elbows was identified. An ophthalmology examination was
unremarkable, with, in particular, no changes in the colour of
the sclerae being noted. An examination of the oral cavityidentified a normal palate with teeth of normal colour and no
evidence of periodontal disease.
The tenascin-X gene is a large gene with 39 exons and is
not amenable to simple DNA analysis. Although no routine
DNA diagnostics are available, serum analysis of tenascin-X
levels has been validated at the DNA level previously.2 Serum
tenascin-X levels appear relatively constant within individuals...