Chronic, Cyclic , Childhood Fevers

My oldest grandchild has had recurrent high  fevers for about four years. They come every 28 days , last from 4 - 8 days like clockwork. She has stomach pain, nausea, headaches, muscle pain, over whelming fatigue, and usually vomiting at least once an episode. The good docs (and there have been many) think it is PFAPA or Familial Mediterranean Fever. Her test for FMF cames back "fuzzy, positive." Every other test, scan, or Xray  has come back negative. They say they cannot definitively diagnose this,
Regarding FMF, my maternal grandmother always said she and all her people were Black Dutch. I have suffered from some type of mixed connective tissue disease from age five. Diagnoses have been everything from encephaliitis, Sjogren's, peripheral neuropathy, rheumatoid arthritis, JRA, and lupus - and a few other strange maladies. My symptoms are very similar to hers, but not in any  rythmic fashion.
Could this be FMF in both of us?

[Alex7777]

I have FMF.  Simple gene test would confirm it.  I had the save fever and stomach pain for two years until the gene test confirmed it.