||1.42x possible increased risk for neuroblastoma
||2x increased risk for neuroblastoma
SNPs clustered in one region of chromosome 6p22 have been linked to increased risk for the exceedingly rare childhood cancer known as neuroblastoma. A study involving 720 patients determined that rs6939340(G;G) genotypes had increased likelihood of neuroblastoma development (odds ratio 1.97, CI: 1.58 to 2.45, p=9.3 x 10-15). At-risk homozygotes diagnosed with neuroblastoma had, on average, more malignant clinical presentation, more aggressive disease, and poorer long-term survival.[PMID 18463370]
Presumably driven primarily by the at-risk homozygotes, the rs6939340(G) allele was considered to be a risk factor, however, there was insufficient data to conclude whether rs6939340(A;G) heterozygotes were actually at any increased risk compared to rs6939340(A;A) "wild-type" homozygotes.[PMID 18463370]
Note that this is an excellent example for putting SNP-associated risks in a relative context of Lifetime Risk. The annual mortality rate for neuroblastoma for everyone combined is 10 per 1 million children in the 0- to 4-year-old age group. Assuming the ~20% of children with the most "at-risk" genotype identified to date, i.e. rs6939340(G;G) homozygotes, have double the risk of the other genotypes, which means their mortality risk has only gone up to ~17 per million, versus the risk for the 80% of individuals with other genotypes going down to ~9 per million. Even if these studies are successfully replicated, odds of 17 out of a million are very very small, so these studies are not useful in predicting disease, even if they may ultimately have benefit in the management of individuals diagnosed with disease.
[PMID 19412175] Common variations in BARD1 influence susceptibility to high-risk neuroblastoma.