MDS/Chromosome 18
 

Hi. I have a good friend (age 57) who has been diagnosed with MDS relating to chromosome 18. This seems like an unusual variation since I haven't seen it mentioned nearly as much (hardly at all) compared to the other chromosomes. His platelet count is 10,000 but WBC and RBC are okay. He's currently getting ATG. Does anyone know anything about this particular variation of MDS? In my searches it seems outcome can vary based on chromosome and I was just wondering if anyone knows where this one stands. Thanks!

I usually refer to this table from 2008, which shows the most commonly affected chromosomes and whether they indicate a relative better or worse prognosis.

Chromosome 18 doesn't appear in the chart, so it must be a less common abnormality, as you've observed.

I spotted a 2006 report of a study of complex chromosomes in MDS and AML patients in which they found that 4 of 17 patients had abnormalities in chromosome 18, so it's not unheard of. However, they were studying only patients who also had chromosome 5 abnormalities, and chromosome 5 is much more predictive.

My wife had a similar situation, with uncommon abnormalities for which we couldn't find research results. Her doctor said that having no abnormalities is better than having any abnormality, that having an non-studied one is better than having one with a known negative prognosis, and having abnormalities that are stable is better than finding different abnormalities from one bone marrow biopsy to the next.