Re-analysis of the Xq27-Xq28 region suggests a weak association of an X-linked gene with sporadic testicular germ cell tumour without cryptorchidism

Background: A testicular germ cell tumour (TGCT) predisposing gene has been mapped to the Xq27 region on the X chromosome. These linkage findings remain to be confirmed by other studies. Methods: In 276 patients and 169 unaffected first-degree male relatives, 12 microsatellite markers covering the candidate region were genotyped and used to study possible association of TGCT with Xq27. Results: In contrast to previously reported linkage of familial TGCT and cryptorchidism with Xq27, we observed an association between the subset of TGCT cases without a family history of TGCT or cryptorchism and marker DXS1193 (p = 0.014). Carriers of minor alleles were at increased risk (odds ratio (OR) 4.7, confidence interval (CI) 1.1-19.6). Conclusion: We found an association on Xq27 in a subset of TGCT cases, which suggests the presence of an X-linked gene that slightly or moderately increases risk to develop sporadic TGCT but not cryptorchidism.