Oculoauricular syndrome explained

Oculoauricular syndrome is a rare genetic condition affecting the eyes and ears. It is due to mutations in the H6 family homeobox 1 (HMX1) gene. It is also known as the Schorderet-Munier-Franceschetti syndrome.

Signs and symptoms

The clinical features of this condition are as follows:

Eyes

• microphthalmia
• coloboma
• nystagmus
• corneal sclerosis
• cataract
• glaucoma
• anterior synechiae
• posterior synechiae
• macular hypoplasia
• rod-cone dystrophy
• divergent strabismus
• posterior embryotoxon

Ears

• malformed pinnae
• low-set pinnae
• crumpled helix
• narrow external acoustic meatus
• coloboma of the lobules

Hearing is normal

Genetics

This condition is inherited in an autosomal recessive manner. The gene responsible is located on the short arm of chromosome 4 (4p16.1)^[1]

Pathogensis

This is not presently understood.

Diagnosis

Differential diagnosis

This includes

• Morning glory syndrome

Epidemiology

This condition has only been described in three families to date (2017).

History

This condition was first described in 1945.^[2] The gene responsible was identified in 2008.^[1]

References

1. Schorderet. D.F.. Nichini. O.. Boisset. G.. Polok. B.. Tiab. L.. Mayeur. H.. Raji. B. de la Houssaye. G. Abitbol. M.M.. Munier. FL. 2008. Mutation in the human homeobox gene NKX5-3 causes an oculo-auricular syndrome. American Journal of Human Genetics. 82. 5. 1178–1184. 10.1016/j.ajhg.2008.03.007. 18423520. 2427260.
2. Franceschetti. A/. Valerio. M.. 1945. Malformations associees des yeux et des oreilles. Confinia Neurologica. 6. 5. 255–257. 10.1159/000105978.