What effects on gene expression in offspring does genomic imprinting have?

If you can't understand what's written .... sigh .... I am not sure you should be studying biology and specially not genetic imprinting. It's a knew biological phenomenon thats still been researched. if you are not in par with understanding scientific text ... you have issues.

So basically in really unscientific words ... means .... say for example you have a protein been made by mother's gene and father's gene. The body needs 500 molecules of that certain protein to function. Too much of that protein inside the body could be bad. So mother's gene will produce 500 molecules of that protein and father's 500 molecules .... now we have 1000 molecules been made which is too much. So the cell needs to shut off one of the genes so that they can balance the proteins been made. So what happens is that .... when the egg and the sperm fertilize, to make the number of protein made be 500 molecules, the mother's or the father's gene will be shut off.
That's just an example and not even an actual example .... just extremely primitive scientific explanation ...

Genomic imprinting is a genetic phenomenon by which certain genes are expressed in a parent-of-origin-specific manner. It is an inheritance process independent of the classical Mendelian inheritance. Imprinted genes are either expressed only from the allele inherited from the mother (eg. H19 or CDKN1C), or in other instances from the allele inherited from the father (eg. IGF2). Here what happens is that only one of the alleles will function (either mom's or dad's).

The phrase "imprinting" was first used to described events in the insect Pseudococcus nipae. In Pseudococcids or mealybugs (Homoptera, Coccoidea) both the male and female develop from a fertilised egg. In females, all chromosomes remain euchromatic and functional. In embryos destined to become males, one haploid set of chromosomes becomes heterochromatinised after the sixth cleavage division and remains so in most tissues; males are thus functionally haploid.

The majority of imprinted genes in mammals have been found to have roles in the control of embryonic growth and development, including development of the placenta. Other imprinted genes are involved in post-natal development, with roles affecting suckling and metabolism.

In insects, imprinting describes the silencing of the paternal genome in males, and thus is involved in sex determination. In mammals, genomic imprinting describes the processes involved in introducing functional inequality between two parental alleles of a gene.