Introduction
Neuhäuser syndrome is an extremely rare genetic disease, in which the specific cause is unknown and there is no diagnostic test. The diagnosis in childhood is usually performed by oculo-neurological criteria (1).
Case report
A 10-year-old male was referred to us from department of pediatrics for routine ocular examination. He was diagnosed with mild mental retardation. There was no significant medical, surgical, family, traumatic, or drug abuse history. Ocular examination was carried out, and his visual acuity was 6/6 in both the eyes. Ocular movements, fundus, and intraocular pressure were normal bilaterally. Slit-lamp/torch examination revealed bilateral corneal diameter of 13 mm (megalocornea) (Figure 1). Keratometry, optical coherence tomography, and B-scan ultrasonography were within the normal limits. Later, a diagnosis of megalocornea-mental retardation (MMR) syndrome was found. No further intervention was done from ophthalmology side.
Figure 1.
Discussion
Megalocornea can be defined as an isolated abnormality inherited by an X-linked mechanism, or it can be associated with other entities (2). Megalocornea (corneal diameter ≥ 13 mm) is associated with mental and neurological impairment and minor anomalies in Neuhäuser syndrome (MMR syndrome) (3). Megalocornea is a defining feature of Neuhäuser syndrome. The genetic cause of this syndrome is currently unknown. The majority of reported cases are associated with an autosomal recessive mode of inheritance (4). Megalocornea, mental retardation, and, presumably, hypotonia are the major manifestations for diagnosis (5).
Various conditions associated with megalocornea are Axenfeld-Rieger syndrome, Peters anomaly, primary congenital glaucoma, aniridia, congenital hereditary endothelial dystrophy, sclerocornea, Frank-ter Haar syndrome, buphthalmos, Crouzon syndrome, Marfan syndrome, albinism, Ritscher-Schinzel syndrome, Wolfram-like syndrome, Lamellar ichthyosis, and osteogenesis imperfecta (6).
References
1. Aviña-Fierro J, Hernández-Aviña D. Síndrome de Neuhauser: su fenotipo facial dismórfico [Neuhauser syndrome: the facial dysmorphic phenotype]. Rev Med Inst Mex Seguro Soc. (2016) 54:106–8.
2. Gutiérrez-Amavizca B, Juárez-Vázquez C, Orozco-Castellanos R, Arnaud L, Macías-Gómez N, Barros-Nuñez P. Neuhauser syndrome: a rare association of megalocornea and mental retardation. Review of the literature and further phenotype delineation. Genet Couns. (2013) 24:185–91.
3. Verloes A, Journel H, Elmer C, Misson J, Le Merrer M, Kaplan J, et al. Heterogeneity versus variability in megalocornea-mental retardation (MMR) syndromes: report of new cases and delineation of 4 probable types. Am J Med Genet. (1993) 46:132–7. doi: 10.1002/ajmg.1320460206
4. Davidson A, Cheong S, Hysi P, Venturini C, Plagnol V, Ruddle J, et al. Association of CHRDL1 mutations and variants with x-linked megalocornea, neuha äuser syndrome and central corneal thickness. PLoS One. (2014) 9:e104163. doi: 10.1371/journal.pone.0104163
5. Santolaya J, Grijalbo A, Delgado A, Erdozaín G. Additional case of Neuhäuser megalocornea and mental retardation syndrome with congenital hypotonia. Am J Med Genet. (1992) 43:609–11. doi: 10.1002/ajmg.1320430321