Figure 2. Subsequent linkage analyses. A: Affected children from the family. Full coloration indicates affected individuals; asterisk indicated esotropic Duane retraction
syndrome (other affected individuals had infantile esotropia). B: Repeated linkage analysis with the same parameters but excluding the 2 unaffected siblings (i.e., using the parents and
all 4 esotropic children) confirmed the linkage to the same regions on chromosomes 3 and 6 with LOD scores of 2.78 and 2.31.
An additional candidate region of 5.5 MB in size on chromosome 17q25.1–25.3 with a LOD score of 2.39 was detected. C: Analysis without the esotropic Duane retraction syndrome patient (i.e., for the 3 infantile esotropes and the parents only)
confirmed linkage to the same regions on chromosome 3 and 6 with LOD scores of 2.00 and 2.32 while the LOD score on chromosome
17 decreased to 1.83.