P390: TWIST related disorders in two Mongolian adolescents: Case reports and review of the literature

Exam revealed a young man who was sitting with his hands folded, smiling, and not disruptive.His speech was a little explosive.He followed commands.There was mild facial asymmetry; his right face was flatter than the left.He had a bifid tongue and clinodactyly on both hands.Calf bulk was normal.There were no features associated with Fragile X or Down Syndrome.Diagnostic Workup: Patient's EEG was normal.Brain MRI showed a reduced anterior commissure.Munson's sign was present on gross exam.Slit-lamp examination showed paracentral thinning and bulging of the cornea, Fleischer's ring, Vogt's striae, and corneal hydrops.Corneal topography revealed inferior steepening consistent with keratoconus.Thus, he was diagnosed with keratoconus at age 25.Chromosome microarray revealed a 247 kb interstitial deletion of 2Q24.2->2Q24.2,which was pathogenic, resulting in deletion of 2 OMIM genes (PSMD14, TBR1).FISH confirmed 2Q24.2 deletion in the proband.His mom tested negative for this deletion.His father's genetic testing results are pending.