Genetics of glucocorticoid-associated osteonecrosis in children with acute lymphoblastic leukemia

Glucocorticoids are important therapy for acute lymphoblastic leukemia (ALL) and their major adverse effect is osteonecrosis. Our goal was to identify genetic and nongenetic risk factors for osteonecrosis. We performed a genome-wide association study of single nucleotide polymorphisms (SNPs) in a discovery cohort comprising 2285 children with ALL, treated on the Children's Oncology Group AALL0232 protocol (NCT00075725), adjusting for covariates. The minor allele at SNP rs10989692 (near the glutamate receptor GRIN3A locus) was associated with osteonecrosis (hazard ratio 5 2.03; P 5 3.59 3 1027). The association was supported by 2 replication cohorts, including 361 children with ALL on St. Jude's Total XV protocol (NCT00137111) and 309 non-ALL patients from Vanderbilt University's BioVU repository treated with glucocorticoids (odds ratio [OR]51.87 and 2.26;P5.063 and .0074, respectively). In ameta-analysis, rs10989692 was also highest ranked (P 5 2.68 3 1028), and the glutamate pathway was the top ranked pathway (P 5 9.8 3 1024). Osteonecrosis-associated glutamate receptor variants were also associated with other vascular phenotypes including cerebral ischemia (OR 5 1.64; P 5 2.5 3 1023), and arterialembolismandthrombosis (OR51.88;P54.231023). In conclusion,osteonecrosiswas associatedwith inheritedvariations near glutamate receptor genes. Further understandingthis associationmay allow interventions to decrease osteonecrosis. These trials are registered at www.clinicaltrials.gov as #NCT00075725 and #NCT00137111.