My husbands mother wad diagnosed with myelodysplastic syndrome in her mid 50's, passed away she was deficient of chromosome 8. Is this hereditary?

Probably not. Even though a history of mds in first degree relatives may slightly increase the overall risk to develop mds, the risk is still minimal and these diseases are usually not hereditary.
Chromosome 8. This is a list of diseases associated to chromosome 8 http://ghr.Nlm.Nih.Gov/chromosome/8/show/conditions. I do not see myelodysplastic syndrome.