Vitamin D and oestrogen receptor polymorphisms in developmental dysplasia of the hip and primary protrusio acetabuli – A preliminary study

Birender Kapoor¹ , Colin Dunlop² , Charles Wynn-Jones³ , Anthony A Fryer⁴ , Richard C Strange⁴ and Nicola Maffulli³

¹Department of Trauma and Orthopaedic Surgery, Arrowe Park Hospital, Arrowe Park Road, Upton, Wirral. CH49 5PE, UK

²Department of Trauma and Orthopaedic Surgery, Ninewells Hospital, Dundee. DD1 9SY, UK

³Department of Trauma and Orthopaedic Surgery, Keele University School of Medicine, University Hospital of North Staffordshire, Thornburrow Drive, Hartshill, Stoke on Trent, Staffordshire, ST4 7QB, UK

⁴Human Genomics Research Group, Institute for Science and Technology in Medicine, Keele University School of Medicine, University Hospital of North Staffordshire, Thornburrow Drive, Hartshill, Stoke on Trent, Staffordshire, ST4 7QB, UK

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Journal of Negative Results in BioMedicine 2007, 6:7doi:10.1186/1477-5751-6-7


Published:	28 June 2007

Abstract

We investigated the association of developmental dysplasia of the hip (DDH) and primary protrusion acetabuli (PPA) with Vitamin D receptor polymorphisms Taq I and Fok I and oestrogen receptor polymorphisms Pvu II and Xba I. 45 patients with DDH and 20 patients with PPA were included in the study. Healthy controls (n = 101) aged 18–60 years were recruited from the same geographical area. The control subjects had a normal acetabular morphology based on a recent pelvic radiograph performed for an unrelated cause. DNA was obtained from all the subjects from peripheral blood. Genotype frequencies were compared in the three groups. The relationship between the genotype and morphology of the hip joint, severity of the disease, age at onset of disease and gender were examined. The oestrogen receptor Xba I wild-type genotype (XX, compared with Xx and xx combined) was more common in the DDH group (55.8%) than controls (37.9%), though this just failed to achieve statistical significance (p = 0.053, odds ratio = 2.1, 95% CI = 0.9–4.6). In the DDH group, homozygosity for the mutant Taq I Vitamin D receptor t allele was associated with higher acetabular index (Mann-Whitney U-test, p = 0.03). Pvu II pp oestrogen receptor genotype was associated with low centre edge angle (p = 0.07). This study suggests a possible correlation between gene polymorphism in the oestrogen and vitamin D receptors and susceptibility to, and severity of DDH. The Taq I vitamin D receptor polymorphisms may be associated with abnormal acetabular morphology leading to DDH while the Xba I oestrogen receptor XX genotype may be associated with increased risk of developing DDH. No such correlations were found in the group with PPA.