Coats plus syndrome

Coats plus syndrome is an inherited condition characterized by Coats disease of the eye alongside abnormalities of the brain, bones, gastrointestinal system, and other body parts.

Overview

Coats plus syndrome is an inherited condition. It is characterized by an eye disorder called Coats disease, which affects the retina—the tissue at the back of the eye that detects light and color. This disorder causes blood vessels in the retina to become abnormally enlarged (dilated) and twisted. These vessels leak fluid, which can eventually cause the layers of the retina to separate, often resulting in vision loss.

Symptoms

Individuals with Coats plus syndrome experience a range of systemic abnormalities:

• Brain abnormalities: These include abnormal deposits of calcium (calcification), the development of fluid-filled pockets called cysts, and the loss of white matter (leukodystrophy). These issues worsen over time, leading to slow growth, movement disorders, seizures, and a decline in intellectual function.
• Bone and blood issues: Patients often have low bone density (osteopenia), causing fragile bones, and a shortage of red blood cells (anemia), which can lead to pale skin (pallor) and extreme fatigue.
• Gastrointestinal and liver complications: Serious or life-threatening issues include abnormal bleeding in the gastrointestinal tract, high blood pressure in the vein supplying the liver (portal hypertension), and liver failure.
• Other features: Less common signs include sparse, prematurely gray hair; malformations of the fingernails and toenails; and skin pigmentation abnormalities, such as light brown patches.

Causes

Coats plus syndrome results from mutations in the CTC1 gene. This gene provides instructions for making a protein that plays an important role in telomeres, the protective structures at the ends of chromosomes. The CTC1 protein works as part of the CST complex, which is involved in the replication of telomeres and helps prevent them from degrading as cells divide.

Mutations in the CTC1 gene impair the function of the CST complex. While researchers are still studying the exact impact on telomere structure, these mutations are linked to the varied signs and symptoms of the syndrome.

Inheritance

This condition is inherited in an autosomal recessive pattern, meaning both copies of the gene in each cell must have mutations. Parents of an affected individual each carry one copy of the mutated gene but typically do not show signs or symptoms of the condition.