Human glia maturation factor-gamma (hGMF-gamma) is a recently identified gene that may be involved in glial differentiation, neural regeneration, and inhibition of tumor cell proliferation. The gene maps to the long arm of chromosome 19 at band q13.2, a region that is frequently deleted in human malignant gliomas and is thus suspected to harbor a glioma tumor suppressor gene. Given the putative role of hGMF-gamma in cell differentiation and proliferation and its localization to chromosome 19q13, this gene is an interesting candidate for the chromosome 19q glioma tumor suppressor gene. To evaluate this possibility, we determined the genomic structure of human hGMF-gamma and performed mutation screening in a series of 41 gliomas with and without allelic loss of chromosome 19q. Mutations were not detected, which suggests that hGMF-gamma is not the chromosome 19q glioma suppressor gene. However, the elucidation of the genomic structure of hGMF-gamma may prove useful in future investigations of hGMF-gamma in the normal adult and developing human nervous system.