Publication Date:
2002-01-01
Description:
PIK3CG, which encodes the catalytic subunit p110γ of phosphoinositide 3-OH-kinase-γ (PI3Kγ), has been assigned to chromosome band 7q22, a region that is frequently deleted in myeloid malignancies. PI3Kγ-mutant mice have hematologic defects and are predisposed to colon cancer. On the basis of these data, PIK3CG was evaluated as a candidate myeloid tumor suppressor gene (TSG). PIK3CG was mapped by fluorescence in situ hybridization adjacent and telomeric to a commonly deleted segment defined previously in myeloid leukemias with breakpoints within 7q22. PIK3CG contains 10 exons and spans approximately 37 kilobases of genomic DNA. Forty leukemias with monosomy 7 or a del(7q) were screened for PIK3CG mutations. Two patients had missense variations affecting residue 859 in the N-terminal catalytic domain of the protein. This allele was also detected in unaffected parents and in 1 of 60 control alleles; it probably represents a polymorphism. PIK3CG is unlikely to act as a recessive TSG in myeloid leukemias with monosomy 7.
Print ISSN:
0006-4971
Electronic ISSN:
1528-0020
Topics:
Biology
,
Medicine