Genetic analysis of congenital cystic adenomatoidmalformation reveals a novel pulmonary gene: Fattyacid binding protein-7 (brain type)Amy Wagner, MD, Amber Stumbaugh, MS, Zachary Tigue, BS,Edmondson Jess, BS, Agnes Paquet, MS, Diana Farmer, MD, FACS,Samuel Hawgood, MDUniversity of California, San Francisco; Virginia Mason MedicalCenter, Seattle, WA

INTRODUCTION: The pathogenesis of congenital cystic adenoma-toid malformation (CCAM) is unknown and its natural history isunpredictable. Fatty acid binding protein-7 (FABP-7) has been de-scribed in brain and breast development, but not in the lung. Weinvestigate gene expression in CCAMs versus control lung tissue, andhypothesize CCAM is a result of an aberration in the signaling path-way during lung development.

METHODS: Under IRB approval, tissue specimens of four groups(fetal CCAM, fetal control, postnatal CCAM, and postnatal control)were examined and microarray analysis was performed. Candidatedifferentially expressed genes were selected with log-odds ratio (B) �0 and False Discovery Rate (FDR) at 0.05. Validation of differentialexpression was achieved at the RNA and protein levels.

RESULTS: FABP-7 was under-expressed in fetal CCAM compared tofetal lung. RT-PCR of FABP-7 expression in fetal CCAM was also under-expressed compared to control, by a 12-fold difference.These findings wereduplicated by Western Blot analysis and immunohisto-chemistry.

CONCLUSIONS: This is the first description of FABP-7 in the hu-man lung. Decreased expression of FABP-7 in fetal CCAM com-pared to normal fetal lung at both the RNA and protein levels sug-gests FABP-7 may have a role in pulmonary development and in thepathogenesis of CCAM.

S39Vol. 205, No. 3S, September 2007 Surgical Forum Abstracts