The present invention relates first, to the identification of a novel retrovirus and the novel nucleotide sequences encoding a retroviral polymerase gene (POL nucleotides) associated with the existence of MDS and MDS associated disorders. The present invention further relates to methods for using the MDS associated retroviral nucleotides for the detection of MDS and MDS associated disorders in patient samples. The present invention also relates to methods for using and targeting the MDS associated retroviral POL nucleotides in gene therapy protocols for the treatment of MDS and MDS associated disorders in patients in need of such treatment. The present invention further relates to diagnostic protocols and kits for the detection of MDS and MDS associated disorders in tissue samples.