Mapping opposing phenotypes onto DDG2P gene pairs, we identified two DDD probands with partially antagonistic dual diagnoses in our cohort, both of whom fitted with our hypothesis: one had pathogenic variants in ANKRD11 (linked with hypertelorism [MIM: 148050]) and SMARCA4 (linked with hypotelorism [MIM: 614609]) but no evidence of abnormal eye morphology; the other had pathogenic variants in HSPG2 (linked with micrognathia [MIM: 255800]) and OPHN1 (linked with mandibular prognathia [MIM: 300486]) but no evidence of abnormal jaw morphology. This evidence concerns the gene HSPG2 and Micrognathia.