Polymorphisms of the glucocorticoid receptor and avascular necrosis of the femoral heads after treatment with corticosteroids

A female patient developed avascular necrosis of the femoral heads after receiving low doses of glucocorticosteroids (GC) for 3 months. Genotyping of the GC receptor (GR) showed that she was heterozygous for the Bcl-1 allele and heterozygous for the N363S allele. Interestingly, these GR variants are both associated with higher sensitivity to glucocorticoids. It is not known whether the GR gene polymorphisms are causally related to osteonecrosis. However, the presence of these GR variants, as a combination present in only 1% of the normal Caucasian population, seems suggestive. Studies are warranted to investigate the importance of polymorphisms related to GC sensitivity.