Genetics of microphthalmos

Abstract

This is a survey of the genetics of microphthalmos and the heritable syndromes in which microphthalmos occurs. New syndromes are delineated such as the autosomal dominant anophthalmos-microphthalmos-coloboma syndrome, the autosomal dominant microphthalmos, microcephaly, lacunar retinal atrophy syndrome, the autosomal recessive anophthalmos-microphthalmos-coloboma syndrome, the autosomal recessive syndrome with anophthalmos or microphthalmos and genital malformations, and the autosomal recessive syndrome with microphthalmos, microcephaly and retinal falciform folds. Nanophthalmos is described as a poorly defined phenotype and rejected as a genotype. Several other genetic entities with microphthalmos are reviewed and recent descriptions are surveyed.

Developmental Basis of Nanophthalmos:MFRPIs Required for both Prenatal Ocular Growth and Postnatal Emmetropization

“…It is defined by a small eye that is usually affected by one or more gross structural defects. Among these are coloboma, AxenfeldRieger's anomaly, cystic outgrowths of retina or surface epithelia, and optic nerve hypoplasia (1,2). These malformations all arise from a diverse set of genetic defects that produce anomalies of early embryonic induction and pattern formation of the optic cup (1,4).…”

“…Among these are coloboma, AxenfeldRieger's anomaly, cystic outgrowths of retina or surface epithelia, and optic nerve hypoplasia (1,2). These malformations all arise from a diverse set of genetic defects that produce anomalies of early embryonic induction and pattern formation of the optic cup (1,4). The few known genes involved in the etiology of human microphthalmia are transcription factors that play important roles in the early formation of the eye, which take place during the first two months of development (5).…”

Superior Lens Coloboma with Superior Rectus Palsy and Congenital Ptosis

“…6 The neural crest cell function may be disrupted due to various genetic and epigenetic influences, leading to disturbances in the development of the choroid, SR and LPS, thus leading to the developmental defect. 2,7,8 The presentation of a superior lens coloboma with monocular elevation deficit and ptosis does not fit into any recognized syndrome.…”

Exudative retinal detachment in nanophthalmos

“…The term nanophthalmos indicates that the eye is small and, in contrast to ordinary microphthalmos, not associated with other ocular malformations (Warburg 1981). As the corrected visual acuity of nanophthalmic patients is usually within the normal range, the condition can easily be overlooked.…”