Nance–Horan syndrome

Nance–Horan syndrome
Other names	X-linked congenital cataracts and microcornea, X-linked cataract–dental syndrome, cataracts-oto-dental syndrome, cataract–dental syndrome, and mesiodens–cataract syndrome.
This condition is inherited in an X-linked dominant manner.
Specialty	Ophthalmology

Nance–Horan syndrome, also known as X-linked congenital cataracts and microcornea, X-linked cataract–dental syndrome, cataracts-oto-dental syndrome, cataract–dental syndrome, and mesiodens–cataract syndrome, is a rare X-linked syndrome characterized by eye and teeth abnormalities, intellectual disability, and facial deformities.^[1][2]

The main ocular sign of Nance–Horan syndrome is a congenital nuclear cataract which results in reduced visual acuity. Other ocular features include microphthalmia, microcornea, strabismus, and nystagmus. Dental features include tapered premolar/molar cusps, supernumerary teeth, screwdriver-shaped incisors, and diastema. Abnormal facial features include anteverted pinnae, prominent and bulbous nose, and long narrow face. 30% of males with Nance–Horan syndrome have intellectual disabilities. Carrier females exhibit less severe clinical symptoms, including lens opacities at the posterior Y-sutures with minimal or no loss of vision, modest face dysmorphism, and dental abnormalities.^[2]

This syndrome is caused by mutations in the Nance Horan gene (NHS) which is located on the short arm of the X chromosome (Xp22.13).^[3]

There is no known cure for this syndrome. Patients usually need ophthalmic surgery and may also need dental surgery. Genetic counseling and screening of the mother's relatives is recommended.^{[citation needed]}

This syndrome was first described by Margaret B. Horan and Walter Elmore Nance in 1974.^[4][5]

• Li, Huajin; Yang, Lizhu; Sun, Zixi; Yuan, Zhisheng; Wu, Shijing; Sui, Ruifang (2018-02-05). "A novel small deletion in the NHS gene associated with Nance-Horan syndrome". Scientific Reports. 8 (1). Springer Science and Business Media LLC. doi:10.1038/s41598-018-20787-2. ISSN 2045-2322. PMC 5799206.
• Yu, Xuelin; Zhao, Yueyue; Yang, Zhenghua; Chen, Xing; Kang, Gangjing (2024). "Genetic research on Nance-Horan syndrome caused by a novel mutation in the NHS gene". Gene. 906. Elsevier BV: 148223. doi:10.1016/j.gene.2024.148223. ISSN 0378-1119. PMID 38286268.