Stargardt Disease Health Article

Definition

Stargardt disease (STGD) is an inherited vision disorder with macular degeneration that typically affects younger people.

Description

STGD is the most common form of inherited macular degeneration (or dystrophy), a disorder of the retina, that affects younger people. The condition is also known as Stargardt macular dystrophy, juvenile macular degeneration, macular dystrophy with flecks, and fundus flavimaculatus.

Common symptoms of STGD include progressive loss of central vision, problems identifying and differentiating colors, and difficulty seeing fine details clearly.

Genetic profile

There are different types of STGD. The most common form is Type 1, which is associated with autosomal recessive inheritance. In this type, there may be no family history of the condition, and it usually affects only one generation. A couple has a 25% chance of having another affected son or daughter once a child is diagnosed with STGD Type 1. This type of STGD is associated with mutations in the ABCA4 (or ABCR) gene, which is located on chromosome 1. This gene is involved in moving vitamin A compounds naturally to and from cells in the retina; these cells are often impaired in STGD.

Other rarer forms of macular dystrophy with symptoms nearly identical to STGD have been called Stargardt-like macular dystrophy types 2, 3, and 4. These are associated with autosomal dominant inheritance. In these types, a family history of the condition is quite common and STGD may be present in several generations of a family tree. A parent with these macular dystrophies has a 50% chance of having an affected son or daughter. Some of these individuals have been found to have mutations in the ELOVL4 gene on chromosome 6.

Demographics

STGD is found worldwide, affecting males and females equally. The incidence for Type 1 is estimated to be between one in 1,600 and one in 15,000 individuals. In all, it accounts for 7% of all retinal dystrophies.

STGD Type 1 is usually diagnosed in individuals under the age of 20 when decreased central vision is the first problem noticed. In contrast, Stargardt-like macular dystrophies and age-related macular degeneration typically first show up in adulthood.