There are several organizations that are dedicated to finding a treatment/cure for SMA and offering support to SMA families.  Those we are most familiar with are listed below, along with their website addresses.

Miracle for Madison & Friends
www.miracleformadison.org

SMA Support
www.smasupport.org

Families of SMA
www.fsma.org

Andrew's Buddies/Fight SMA
www.fightsma.com

Spinal Muscular Atrophy Foundation
www.smafoundation.org