Using a positional candidate gene approach, we analyzed the BMP4 (Bone Morphogenetic Protein-4) gene and identified a frameshift mutation (c.226del2, p.S76fs104X) that segregated with AM, retinal dystrophy, myopia, brain anomalies, and polydactyly in a family and a nonconservative missense mutation (c.278A-->G, p.E93G) in a highly conserved base in another family.
It was previously reported that the BMP family was correlated with the morphogenesis of digits and ocular development, and Bmp4 heterozygous null mice revealed skeletal abnormalities including polydactyly and ocular anterior segment abnormalities.