Lenz microphthalmia syndrome ... (Lenz microphthalmia syndrome) - Gen BCOR.  

Microphthalmia syndrome Lenz is a disorder characterized by abnormal development of the eye and various other parts of the body. Ocular abnormalities associated with Syndrome Lenz microphthalmia may affect one or both eyes. Signs and symptoms associated with this disease may include microphthalmia, anophthalmia, cataract, nystagmus, coloboma, and increased risk of glaucoma. Often, affected individuals may have abnormalities of the ears, teeth, hands, skeleton and urinary system. Less often, they have heart defects found in affected individuals. Many people will have developmental delays or intellectual disabilities ranging from mild to severe.

This process is due to changes in the BCOR gene, located on the short arm of chromosome X (Xp11.4). This gene encodes a protein known as corepressor BCL6. This protein can not bind to DNA by itself but interacts with other DNA - binding proteins to suppress the activity of certain genes. In this case, the corepressor BCL6 is associated with DNA binding protein encoded from the BCL6 gene. The BCL6 gene plays an important role in the function and survival of certain immune system cells. The BCOR gene is active throughout the body, not only in the immune system. This widespread activity suggests that BCL6 co - repressor has other functions besides its interaction with BCL6 protein. The BCL6 co - repressor appears to play a critical role in early embryonic development, including the formation of the eyes and other tissues and organs. In addition, it is believed that the BCL6 co - repressor may also be involved in the specification of the left and right of the organism in the developing embryo sides.

It has identified a mutation in the gene in a family BCOR with Lenz microphthalmia syndrome. This mutation changes a single amino acid in the correpressor BCL6, which alters the protein structure. Specifically, the mutation replaces the amino acid proline amino acid leucine at position 85 (Pro85Leu). Because the correpressor BCL6 plays an essential role in the early development, a defective version of the protein disrupts normal eye formation and various other organs and tissues before birth.

This disease is inherited in a recessive X - linked pattern in males, an altered copy of the gene in each cell is sufficient to express the disease. In women, a mutation would have to happen in both copies of the gene for the disease to be expressed. Because it is unlikely that women have two altered copies of this gene, males are affected by X - linked recessive disorders much more frequently than women. A feature of the X - linked inheritance is that fathers can not pass X - linked traits to their sons chromosome. Microphthalmia syndrome Lenz has been identified only in males.

Tests in IVAMI: in IVAMI perform detection of mutations associated with Lenz microphthalmia syndrome by complete PCR amplification of exons BCOR gene, and subsequent sequencing.