MedGen

Mutations in the CRYBB2 gene have been found to cause several types of cataract, which have been described as congenital cerulean, 'blue dot,' Coppock-like, sutural with punctate and cerulean opacities, pulverulent embryonal, pulverulent with cortical opacities, dense posterior star-shaped subcapsular with pulverulent opacities in the cortical and embryonal regions, and dense embryonal. Before it was known that mutations in the CRYBB2 gene cause several types of cataract, the preferred title of this entry was 'Cataract, Congenital, Cerulean Type 2,' with the symbol CCA2. [from OMIM]

Cerulean cataract, first described by Vogt (1922), is an autosomal dominant, early-onset, bilateral cataract with complete penetrance. Newborns appear asymptomatic until the age of 18 to 24 months, at which time they can be clinically diagnosed by slit-lamp examination through the appearance of tiny blue or white opacities that form first in the superficial layers of the fetal lens nucleus. The opacities progress throughout the adult lens nucleus and the cortex, forming concentric layers, with central lesions oriented radially. Histologically the lesions appear to be tapered cavities between lens fibers. Progression of the cataract is slow, such that patients may have lens extractions between the ages of 16 and 35 years (Armitage et al., 1995). The preferred title/symbol of this entry was formerly 'Cataract, Congenital, Cerulean Type, 1; CCA1.' [from OMIM]

A rare benign follicular hamartoma that develops primarily on the face of adults, with a particular predilection for the back of the nose, but also on the neck or scalp. It presents as a solitary hemispheric flesh-colored nodule with a central pore or black dot that may contain a tuft of hair. [from ORDO]

A form of telangiectasis characterized by a central elevated red dot the size of a pinhead, representing an arteriole, with numerous small blood vessels that radiate out thereby resembling the legs of a spider. Characteristically, compression of the central arteriole causes the entire lesion to blanch, and the lesion quickly refills once the compression is released. [from HPO]

This anomaly, also known as Mittendorf dot, is a benign, nonprogressive recognizable lesion that does not cause visual impairment. However, it can resemble a pathological congenital or acquired cataract lesion which may enlarge and cause visual impairment. The dot appears as a black speck that ranges in size from the dot made by a sharp pencil point to the size of a poppy seed. It is usually well defined, although occasionally there may be irregular, fine lines radiating outward from the dot. [from HPO]

Epithelial basement membrane corneal dystrophy (EBMD) is a common bilateral epithelial dystrophy characterized mainly by sheet-like areas of basement membrane originating from the basal epithelial cells of the corneal epithelium and extending superficially into the epithelium. Slit lamp examination may reveal dots, maps, grayish epithelial fingerprint lines, blebs, nets, or any combination of these patterns. Histologic analysis shows abnormal redundant basement membrane and intraepithelial lacunae filled with cellular debris. Most patients are asymptomatic before the age of 30 years; some may have recurrent erosions, the frequency of which declines with age, and a loss of vision due to surface irregularity (summary by Boutboul et al., 2006). [from OMIM]

Accumulation of blood located in the retina's inner nuclear and outer plexiform layers, and having a dot-like or blot-like shape. THe shape results from intraretinal compression, restricting the hemorrhages within a specific location. [from HPO]

A rare, genetic, hyperpigmentation of the skin disease characterized by adulthood-onset of reticular, reddish-brown to dark-brown, macular and/or comedone-like, hyperkeratotic papules with hypopigmented macules, predominantly affecting flexural areas and, on occasion, progressing to involve trunk and acral regions. Histologically, epidermal acanthosis, thin, branch-like, rete ridges, and a tendency for acantholysis and pigmentary incontinence is observed. [from ORDO]