There is some evidence that points to auto-immune diseases running in families, but it isn't really known how or why or linked to anything concrete yet.
It's very interesting that you all have such similar illnesses, isn't it?
Lynnwood, Lupus & Sjogren's Moderator, Dx: 2002DIAGNOSING LUPUS & HW's LUPUS 101
"Life is far too important to be taken seriously." - Oscar Wilde