PITX3: A highly recurrent duplication mutation (c.640_656dup17bp) in the human gene for paired-like homeodomain transcription factor 3 (PITX3) on chromosome 10q was first discovered in families with autosomal dominant cataract and anterior segment mesenchymal dysgenesis (ASMD) [93]. The gene discussed is PITX3; the disease is anterior segment dysgenesis.