Macular Dystrophy, Patterned 3

Clinical Characteristics
Ocular Features: 

This condition has been found in an extended pedigree among peoples originating in the West Indies.  Vision loss is noted after the age of 50 years but clinical evidence can be seen in the fourth or fifth decades. The findings are primarily in the retinal pigment epithelium but Bruch's membrane is also involved.  Choroidal neovascularization and macular scarring may be present. The fundus pigmentary pattern has been described as resembling "dried-out soil" or crocodile skin.  In late stages the fundus picture resembles retinitis pigmentosa with loss of the RPE and photoreceptors.  The loss of photoreceptors continues throughout life. An 85 year old woman with light perception only has been described. 

In early stages the full-field ERG can be nomal but later rod and cone responses are severely reduced.  The OCT may show scalloped elevation at the borders of the scalloped patches corresponding to the irregular thickness of the RPE and Bruch membrance.

Knockout mice have both thickened and thinned areas of the Bruch membrane.

Systemic Features: 

No systemic abnormalities have been reported.

Genetics

This autosomal dominant condition results from heterozygous mutations in MAPKAPK3 (3p21.3), a mitogene-activated kinase of the p38 signaling pathway.  It is highly expressed in the RPE.

Treatment
Treatment Options: 

No treatment is available.

References
Article Title: 

A dominant mutation in MAPKAPK3, an actor of p38 signaling pathway, causes a new retinal dystrophy involving Bruch's membrane and retinal pigment epithelium

Meunier I, Lenaers G, Bocquet B, Baudoin C, Piro-Megy C, Cubizolle A, Quiles M, Jean-Charles A, Cohen SY, Merle H, Gaudric A, Labesse G, Manes G, Pequignot M, Cazevieille C, Dhaenens CM, Fichard A, Ronkina N, Arthur SJ, Gaestel M, Hamel CP. A dominant mutation in MAPKAPK3, an actor of p38 signaling pathway, causes a new retinal dystrophy involving Bruch's membrane and retinal pigment epithelium. Hum Mol Genet. 2016 Mar 1;25(5):916-26.

PubMed ID: 
26744326

References

Jean-Charles A, Merle H, Audo I, Desoudin C, Bocquet B, Baudoin C, Sidibe M, Mauget-Faysse M, Wolff B, Fichard A, Lenaers G, Sahel JA, Gaudric A, Cohen SY, Hamel CP, Meunier I. Martinique Crinkled Retinal Pigment Epitheliopathy: Clinical Stages and Pathophysiologic Insights. Ophthalmology. 2016 Oct;123(10):2196-204.

PubMedID: 27474146

Meunier I, Lenaers G, Bocquet B, Baudoin C, Piro-Megy C, Cubizolle A, Quiles M, Jean-Charles A, Cohen SY, Merle H, Gaudric A, Labesse G, Manes G, Pequignot M, Cazevieille C, Dhaenens CM, Fichard A, Ronkina N, Arthur SJ, Gaestel M, Hamel CP. A dominant mutation in MAPKAPK3, an actor of p38 signaling pathway, causes a new retinal dystrophy involving Bruch's membrane and retinal pigment epithelium. Hum Mol Genet. 2016 Mar 1;25(5):916-26.

PubMedID: 26744326