Figure 3.

Fusion of the fourth and fifth suborbital bones (SO4+5) demonstrates a left-sided asymmetric genetic basis. The fourth and fifth suborbital bones (dashed box in A and B) were scored separately on the right (A, C, and E) and left sides (B, D, and F), as demonstrated using specimen 174 from our Asty12 pedigree. Bones were present either as separate elements (the wild-type surface phenotype) (D) or fused together (C). The total area of the bones (E and F) demonstrated a genetic basis in our pedigree (see Figure 6 and Figure 7). One marker, 112A, demonstrated a LOD value >3.0 on the left (I), but not the right (G), side of the head. Effect plots reveal an intermediate dominant effect for 112A (J), on the left side only (compare with H). MQM analyses identified one selected cofactor on the right side (233D) (K). On the left side, the same genetic locus (112A) identified through one-scan mapping was identified using MQM, along with one cofactor (NYU31) (L). Bars: 3 mm in A and B (11×) and 1 mm in C and D (20×). Black trace in G and I represents results of MR mapping method.