Another article that lists the median survival as age 35 is titled: Bone marrow failure: a child is not just a small adult (but an adult can have a childhood disease). You can access the full-text article from this link. Click on the title (4th one down) Shwachman-Diamond America Medical Articles
For more resources to quote from, you can also see the new article titled: Shwachman Diamond Syndrome: an emergency challenge which can be accessed at this link: Shwachman-Diamond Syndrome Articles it is the second article on the page—click on the title and the PDF full text will appear. Here is a quote from this article (P 12):
“Alter et Al (1997) reported a median survival age older than 35 years for all patients with SDS. For those patients whose course is complicated by Aplastic anemia, the median survival age is 24 years, while those patients whose course is complicated by leukemia have a median survival age of 10 years.”