Unilateral vocal fold agenesis: an unusual cause of dysphonia. Unilateral vocal fold agenesis is a rare congenital laryngeal anomaly. To our knowledge, there have been no published reports about this clinical entity to date. A 6-year-old female patient was referred to our practice for persistent hoarseness of voice since birth. On physical examination, her voice was hoarse and reduced in volume. She had facial features typical of Down syndrome and macroglossia. Laryngeal examination revealed the absence of the right vocal fold. She had no further evaluation or treatment.