Low-set ears are a craniofacial anomaly in which the superior helix of the auricle lies below the horizontal line drawn between the inner canthi of the eyes. This feature is commonly observed in congenital and genetic syndromes, including Down, Turner, Noonan, Apert, and Potter’s sequence.

Pathophysiology

Normal physiology:

• During embryogenesis, the external ear develops from the first and second branchial arches and gradually migrates cranially to its normal position.

Abnormal physiology (low-set ears):

• Arrested or abnormal migration of the auricle results in the ears being positioned lower than expected.

• Reflects underlying chromosomal or developmental disturbances affecting craniofacial morphogenesis.

• Often accompanied by other dysmorphic features or systemic anomalies (e.g., renal, cardiac).

Associated findings: May co-exist with micrognathia, cleft palate, hypertelorism, or other stigmata of genetic syndromes.

Examination Technique

• Patient positioning: Place the patient upright in neutral head position.

• Assessment line: Draw an imaginary horizontal line from the inner canthi of the eyes across to the auricle.

• Observation: Determine whether the superior helix lies below this line.

• Documentation: Note whether the finding is unilateral or bilateral, associated anomalies, and any family history of congenital syndromes.

Clinical Features

Differential Diagnosis

Special populations

Elderly: Low-set ears are congenital; not acquired later in life, but ear position may appear altered due to age-related changes in facial anatomy.

Pediatric patients:

• Key group for assessment since low-set ears often serve as the first clue to syndromic diagnosis.

• Workup may include genetic testing, echocardiography, and renal ultrasound due to associated anomalies.

Limitations

• Mild variations may be within normal phenotypic range.

• Head shape and patient positioning can alter the visual impression.

• Should not be diagnosed in isolation—interpret with other clinical features.

Patient Counseling

• Explain that low-set ears themselves are harmless, but may signal an underlying genetic or congenital condition.

• Recommend further evaluation if associated anomalies are present (cardiac, renal, craniofacial).

• Reassure families that isolated cases without other findings typically have no impact on hearing or development.

Conclusion

Low-set ears are a craniofacial dysmorphic feature best recognized by comparing the auricle’s position to the inner canthi line. Though not harmful in isolation, they frequently indicate genetic syndromes or congenital anomalies, making early recognition and multidisciplinary evaluation crucial.

References

1. Jones KL, Jones MC, del Campo M. Smith’s Recognizable Patterns of Human Malformation. 8th ed. Philadelphia: Elsevier; 2021.

2. Stevenson RE, Hall JG, Everman DB, Solomon BD. Human Malformations and Related Anomalies. 3rd ed. Oxford: Oxford University Press; 2015.

3. Allanson JE, Richter S. From genotype to phenotype: A clinical perspective. Am J Med Genet C Semin Med Genet. 2020;184(3):508–516.

4. Carey JC. Dysmorphology, genetic syndromes, and congenital anomalies. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia: Elsevier; 2023.