Nance-Horan Syndrome

Alternative Names

  • NHS
  • Cataract-Dental Syndrome
  • Cataract, X-Linked, With Hutchinsonian Teeth
  • Mesiodens-Cataract Syndrome

Associated Genes

NHS Gene
Back to search Result
WHO-ICD-10 version:2010

Congenital malformations, deformations and chromosomal abnormalities

Other congenital malformations

OMIM Number

302350

Mode of Inheritance

X-linked dominant

Gene Map Locus

Xp22.2-p22.1

Description

Nance-Horan syndrome is a rare genetic disorder that may be evident at birth in male patients.  It is characterized by teeth abnormalities and cataracts, resulting in poor vision.  Additional eye abnormalities are also often present, including a very small cornea and nystagmus.  In about 30% of the cases, intellectual impairment is observed with inter- and intrafamilial variability.  If present, intellectual impairment is usually mild or moderate, without motor delay, but in 20% of cases it is severe/profound and associated with autistic features.  The range and severity of symptoms may vary greatly from one person to another, even among affected members of the same family. 

Diagnosis of Nance-Horan syndrome is based on clinical findings.  Visually significant cataracts need to be removed early to allow for normal visual maturation.  Glaucoma could be treated medically or surgically depending on the type and severity.  Dental surgery may be required for at-risk males and females.

Molecular Genetics

Mutations within the NHS gene (mapped to Xp22.2) are the cause of Nance-Horan syndrome and these mutations typically result in a truncated protein.  The expression of two NHS isoforms, NHS-A and NHS-1A, and differences in the subcellular localization of these isoforms may partly explain the various clinical manifestations. 

Epidemiology in the Arab World

View Map
Subject IDCountrySexFamily HistoryParental ConsanguinityHPO TermsVariantZygosityMode of InheritanceReferenceRemarks
302350.1.1Saudi ArabiaMaleYesNo Developmental cataract; Microcornea; Abn...NM_001291867.2:c.2295delHemizygousAutosomal, RecessiveKhan et al. 2012; Patel et al. 2017 Belongs to a large m...
302350.1.2Saudi ArabiaFemaleYesNo Developmental cataract; Microcornea; Abn...NM_001291867.2:c.2295delHeterozygousAutosomal, RecessiveKhan et al. 2012; Patel et al. 2017 Sister of 302350.1.1
302350.1.3Saudi ArabiaMaleYesNo Developmental cataract; Microcornea; Abn...NM_001291867.2:c.2295delHemizygousAutosomal, RecessiveKhan et al. 2012; Patel et al. 2017 Nephew of 302350.1.1
302350.1.4Saudi ArabiaMaleYesNo Developmental cataract; Microcornea; Abn...NM_001291867.2:c.2295delHemizygousAutosomal, RecessiveKhan et al. 2012; Patel et al. 2017 Nephew of 302350.1.1
302350.1.5Saudi ArabiaMaleYesNo Developmental cataract; Microcornea; Abn...NM_001291867.2:c.2295delHemizygousAutosomal, RecessiveKhan et al. 2012; Patel et al. 2017 Nephew of 302350.1.1
302350.1.6Saudi ArabiaMaleYesNo Developmental cataract; Microcornea; Glo...NM_001291867.2:c.2295delHemizygousAutosomal, RecessiveKhan et al. 2012; Patel et al. 2017 Nephew of 302350.1.1
302350.1.G.1Saudi ArabiaFemaleYesNo Abnormal facial shapeNM_001291867.2:c.2295delHeterozygousAutosomal, RecessiveKhan et al. 2012 4 asymptomatic femal...

Other Reports

Saudi Arabia

Khan et al. (2012) identified a novel NHS mutation (c.2232delG) in a family with seven affected members with congenital or infantile cataract and facial dysmorphism.  Sixteen family members were studied; two affected and six asymptomatic females, five affected and three asymptomatic males.  The six asymptomatic females aged between 4-35 years old; four had posterior Y-suture centered lens opacities and exhibited the facial dysmorphism, the fifth asymptomatic girl had scattered fine punctate lens opacities, while the sixth had clear lenses.  The NHS mutation was also found in the four asymptomatic girls with Y-centered lens opacities but not the other two asymptomatic girls or in the three asymptomatic males (who had clear lenses).

Tunisia

Chograni et al (2011) described a Tunisian family with Nance-Horan Syndrome.  The family included three affected brothers with clinical presentation consistent with NHS.  All three had bilateral total nuclear cataract with microphthalmia, and moderate to severe mental retardation.  Neurological examination revealed ligamentous laxity of the fingers, stereotyped hands and asymmetric bodies.  One of the patients had neonatal hypotonia and cardiac anomaly. Microcornea, nystagmus, or strabismus was not present, neither were the typical screwdriver blade shaped incisors.  Parents were consanguineous, and healthy, as were another brother and sister.  Segregation analysis and mutation screening identified a missense mutation in the NHS gene in hemizygous state in all affected patients and in a heterozygous state in the mother.

© CAGS 2024. All rights reserved.