Pulmonary Vasculopathy Associated with FIGF Gene Mutation.

Vascular endothelial growth factor (VEGF)-D is capable of inducing angiogenesis and lymphangiogenesis through signaling via VEGF receptor (VEGFR)-2 and VEGFR-3, respectively. Mutations in the FIGF (c-fos-induced growth factor) gene encoding VEGF-D have not been reported previously. We describe a young male with a hemizygous mutation in the X-chromosome gene FIGF (c.352 G>A) associated with early childhood respiratory deficiency. Histologically, lungs showed ectatic pulmonary arteries and pulmonary veins. The mutation resulted in a substitution of valine to methionine at residue 118 of the VEGF-D protein. The resultant mutant protein had increased dimerization, induced elevated VEGFR-2 signaling, and caused aberrant angiogenesis in vivo. Our observations characterize a new subtype of congenital diffuse lung disease, provide a histological correlate, and support a critical role for VEGF-D in lung vascular development and homeostasis.