Anterior segment mesenchymal dysgenesis, or simply anterior segment dysgenesis (ASD), is a failure of the normal development of the tissues of the
anterior segment of the eye. It leads to anomalies in the structure of the mature anterior segment, associated with an increased risk of
glaucoma and
corneal opacity.
Peters' (frequently misspelled as Peter's) anomaly is a specific type of
mesenchymal anterior segment dysgenesis, in which there is central corneal leukoma, adhesions of the
iris and
cornea and abnormalities of the posterior
corneal stroma,
Descemet's membrane,
corneal endothelium,
lens and
anterior chamber.
Pathophysiology
Several gene mutations have been identified underlying these anomalies, with the majority of ASD genes encoding
transcriptional regulators
Regulation of gene expression, or gene regulation, includes a wide range of mechanisms that are used by cells to increase or decrease the production of specific gene products (protein or RNA). Sophisticated programs of gene expression are wide ...
. In this review, the role of the ASD genes, ''
PITX2'' and ''
FOXC1'', is considered in relation to the embryology of the anterior segment, the biochemical function of these proteins, and their role in development and disease aetiology. The emerging view is that these genes act in concert to specify a population of mesenchymal progenitor cells, mainly of
neural crest origin, as they migrate anteriorly around the embryonic
optic cup. These same genes then regulate
mesenchymal cell
Mesenchymal stem cells (MSCs) also known as mesenchymal stromal cells or medicinal signaling cells are multipotent stromal cells that can differentiate into a variety of cell types, including osteoblasts (bone cells), chondrocytes (cartilage ce ...
differentiation to give rise to distinct anterior segment tissues. Development appears critically sensitive to
gene dosage, and variation in the normal level of
transcription factor activity causes a range of anterior segment anomalies. Interplay between ''PITX2'' and ''FOXC1'' in the development of different anterior segment tissues may partly explain the phenotypic variability and the genetic heterogeneity characteristic of ASD. In the most recent research, the ''PAX6'' gene has been implicated in Peters' Anomaly
Diagnosis
Management
History
This congenital anomaly was first described by German ophthalmologist Albert Peters (1862–1938).
References
External links
{{Transcription factor/coregulator deficiencies
Eye diseases