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The eye
Published in Angus Clarke, Alex Murray, Julian Sampson, Harper's Practical Genetic Counselling, 2019
Numerous types of congenital cataract exist, with all forms of inheritance recorded. The incidence is around 1 in 250 births. Environmental causes (e.g. the toxoplasmosis, other [syphilis, varicella-zoster, parvovirus B19], rubella, cytomegalovirus and herpes simplex [TORCH] congenital infections) and metabolic and other primary disorders (e.g. galactosaemia, hypoparathyroidism, peroxisomal disorders) must be excluded, and syndromal associations sought (e.g. Conradi disease, Lowe syndrome, cerebro-oculo-facio-skeletal [COFS], DNA repair defects). Consider the sex-linked Nance-Horan syndrome in severely affected male infants (females tend to be affected more mildly).
Great clinical variability of Nance Horan syndrome due to deleterious NHS mutations in two unrelated Spanish families
Published in Ophthalmic Genetics, 2019
V. Hernández, I. Pascual-Camps, M. J. Aparisi, M. Martínez-Matilla, F. Martínez, J. A Cerón, L. Pedrola
Nance-Horan syndrome (NHS; OMIM: 302350) is a rare congenital disorder with unknown prevalence, probably because it is often misdiagnosed (https://rarediseases.org/rare-diseases/nance-horan-syndrome/). It was initially described in 1974 by two research groups: Horan et al. in Australia (1); and Nance et al. in the United States (2). This syndrome is caused by mutations in the NHS gene (3), which has key functions in the regulation of eye, teeth, brain and craniofacial development. Brooks et al 2010 (4) demonstrated that NHS protein is an actin regulatory protein with a relevant role in cell morphology, involved in the embryological development of the lens, brain, heart and limbic system (5).This explains the pleiotropic effects caused by these mutations (6). Its inheritance pattern is X-linked dominant with high penetrance and variable expressivity among males and females. Female patients often manifest similar but less severe features than male patients (6).
Nance–Horan syndrome in females due to a balanced X;1 translocation that disrupts the NHS gene: Familial case report and review of the literature
Published in Ophthalmic Genetics, 2018
Laura Gómez-Laguna, Alejandro Martínez-Herrera, Alejandra del Pilar Reyes-de la Rosa, Constanza García-Delgado, Karem Nieto-Martínez, Fernando Fernández-Ramírez, Tania Yanet Valderrama-Atayupanqui, Ariadna Berenice Morales-Jiménez, Judith Villa-Morales, Susana Kofman, Alicia Cervantes, Verónica Fabiola Morán-Barroso
The Nance–Horan syndrome (NHS, MIM 302350) is an X-linked disorder characterized by congenital cataract, microcornea, microphthalmia, a large and narrow face with a prominent and bulbous nose, anteverted pinnae, and dental anomalies that include supernumerary incisors, diastema, screwdriver blade-shaped, cone-shaped or peg-shaped incisors, and tapered premolar and molar cusps (1–6). Up to 30% of NHS affected males have intellectual disability (5). Heterozygous females have less severe features, such as lens opacities around the posterior Y-suture, facial, and dental characteristics (4,7,8).
Further delineation of the oculoauricular syndrome phenotype: A new family with a novel truncating HMX1 mutation
Published in Ophthalmic Genetics, 2018
Ghada M.H. Abdel-Salam, Mohamed S. Abdel-Hamid, Mennat I. Mehrez, Ahmad M. Kamal, Mohamed B. Taher, Hanan H. Afifi
Despite the overlapping features of Nance-Horan syndrome (NHS) and OAS but they are genetically distinct. NHS is classically described as X-linked whereas the recessive nature of the family described herein allowed us to initially distinguish OAS from NHS. Moreover, absence of intellectual disability and the characteristic dental anomalies reported in NHS such as screwdriver-shaped incisors and bud molars were in favor of OAS(14). This was confirmed by the genetic testing.