GE = Genetically Engineered which is exactly the same as
GM = Genetically Modified.
GMO = "Genetically Modified Organism" is often used in places where the correct term would be "GM". GA = Genetically altered is usually not abbreviated but means the same as GE.

The biotech corporations want people use the term "genetically modified" (GM) as their PR experts think it sounds less threatening. We don't accept this propaganda trick and use "genetically engineered" (GE) because it gives a more adequate idea of what it is about - an unnatural manipulation of genes.

GE is also the same as transgenic and recombinant. These terms are used by biotech scientists. We avoid these technical words here.