Author(s): Siddiqi M.; Graham S.; O’Hare J.
Source: Osteoporosis International; 2018; vol. 29 (no. 1)
Publication Date: 2018
Publication Type(s): Conference Abstract
Available at Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA – from SpringerLink – Medicine
Abstract:Introduction: Ossification of posterior longitudinal ligament (OPLL) is a hyperostotic condition resulting in abnormal calcification of the posterior longitudinal ligament of the spine and presents with varying neurological symptoms [1]. Prevalence rates are higher amongst the Japanese population between 1.9% and 4.5% as compared to 0.12% in Caucasians [1]. Osteopathia striata cranial sclerosis (OSCS) is a rare X-linked dominant condition characterised by linear bony striations affecting the long bones and pelvis in combination with cranial sclerosis. Prevalence is estimated at 1 per 10 million. It displays high phenotypic variability, with lethality in most affected males. Clinical features may include craniofacial dysmorphism, learning difficulties and cardiac malformations [2]. Case presentation: A 35 year old Caucasian woman, with no significant past medical or family history, presented with signs of cervical myelopathy. Computed topography and magnetic resonance imaging scans of the cervical spine demonstrated OPLL at C3-C4 [Fig.1] with evidence of cord impingement. The patient underwent a C3/C4 laminectomy. A skeletal survey showed thickening and increased density in the skull vault and prominent vertical striations in the long bones [Fig.2]. All biochemical parameters were normal including bone turnover markers. Subsequent genetic testing confirmed a diagnosis of OSCS. Discussion: OSCS is known to be due to mutations in the gene encoding AMER1/ WTX (Wilms’ tumor on X chromosome), a repressor for WNT signalling, which plays an anabolic role in bone formation by osteoblasts. Perturbation of this pathway is involved in other sclerosing bone dysplasias. There is also a relationship between OPLL and the WNT pathway. Presence of bone sclerosis is a prominent feature in OSCS and is in keeping with the evidence that other sclerosing bone phenotypes have been explained by increased WNT signalling causing increased bone formation. Although rare, OSCS carries a high disease burden and has significant genetic implications. It should be considered when investigating cases of OPLL. This is, to our knowledge, the first presented case of an association between OPLL and OSCS.
Database: EMBASE