Identification of three novel mutations of the noggin gene in patients with fibrodysplasia ossificans progressiva.

Abstract

We report noggin mutations in three Spanish families with fibrodysplasia ossificans progressiva (FOP). The three propositi have typical FOP findings; in the first and third families the parents are unaffected, while in the second family the father is partially affected. DNA of the three propositi and their parents was screened by sequencing for mutations in the noggin gene (NOG). Sequencing indicated a G to C mutation at nucleotide 274 of the NOG gene in the first propositus, encoding for the G92R substitution at the peptide level; this first mutation is de novo, the corresponding change not being observed in parents. In the second propositus, a G to T mutation at nucleotide 271 encodes for the G91C substitution, transmitted in the corresponding family by the partially affected father. In the third propositus, sequencing indicated a G to A mutation at nucleotide 275, encoding for the G92E substitution; this third mutation is de novo. All three mutations, as well as the Delta42 deletion already reported, resulted in the alteration of the portion of the NOG gene at positions 265-282, encoding for the potential N-myristoylation site at residues 89-GGGGGA-94.