This ENU-induced mutation was isolated in a screen at the University of Pittsburgh. The causitive molecular lesion for the cardiovascular phenotypes is a C to T substitution at coding nucleotide postition 3184 in exon 16 of the cDNA (c.3184C>T, NM_010060). This changes the glutamine residue to a stop codon at position 1062 in the encoded protein (p.Q1062*).