Constitutional & Familial Issues: Genetics of PPB

We have learned over the past several years that some children with PPB or their relatives (currently estimated to be 40% of PPB cases) may have other cysts or tumor growths (see Registry Publications Priest 1996, Boman 2006, Priest 2009). The most common associated problems are multifocal or bilateral lung cysts (sometimes including bilateral PPB), benign cystic kidney tumors (particularly cystic nephroma), rhabdomyosarcoma and other soft tissue neoplasms, benign thyroid nodules or thyroid cancer, and possibly ovarian Sertoli-Leydig cell tumors and dysgerminoma, testicular seminoma, other gonadal germ cell tumors and some leukemias. More information is available on this website at For Doctors, Constitutional and Familial PPB.

In April 2009, The PPB Registry and collaborators at Washington University St. Louis and other institutions reported germline loss-of-function DICER1 mutations in 11 families in which there were PPB, lung cysts, cystic nephroma and/or rhabdomyosarcoma. This research has been published. (see Registry Publications Hill Science 2009). This is the first genetic abnormality associated with PPB. This finding is probably the first step to understanding the events underlying the familial manifestations of PPB. For complete meeting abstract: Genetics of PPB

To learn the extent to which DICER1 mutations may explain PPB, this study must continue and include more families and especially include apparently sporadic cases of PPB. To learn more about the PPB Registry Genetic Study contact the Registry or go to the PPB Genetic Study website www.ppbgeneticstudy.org.

We encourage all children with PPB and their families to consider participating in this important research effort. Thank you.