SNP Shot: Genomic Insights

Bloom syndrome is a genetic condition passed down through families. It is defined by three major characteristics: shorter than average height, a skin rash triggered by sunlight, and a significantly higher chance of developing cancer.

From birth, individuals with Bloom syndrome typically have a height and weight that is lower than 97% of the general population. As adults, they rarely grow taller than 5 feet.

A hallmark of Bloom syndrome is skin that is highly sensitive to sunlight. This often results in a butterfly-shaped, red rash across the nose and cheeks. This rash may also appear on other sun-exposed areas like the hands and forearms. Tiny clusters of widened blood vessels, called telangiectases, commonly develop within the rash, and can also be found in the eyes. Additional skin changes may include areas of lighter (hypopigmentation) or darker (hyperpigmentation) skin. These patches occur on areas not exposed to sunlight and are not linked to the sun-induced rashes.

A key concern for individuals with Bloom syndrome is an elevated risk of cancer. While any type of cancer can occur, it tends to appear at a younger age compared to the general population. Furthermore, individuals may develop multiple types of cancer during their lifetime.

People with Bloom syndrome may have a higher-pitched voice and distinct facial features such as a long, narrow face, a small lower jaw, and noticeable nose and ears. Other possible features include learning difficulties, an increased susceptibility to diabetes and chronic obstructive pulmonary disease (COPD), and mild immune system issues that can lead to frequent upper respiratory infections, ear infections, and lung infections, particularly in infancy. Males with Bloom syndrome are usually infertile due to a lack of sperm production. Women often have reduced fertility and experience earlier menopause.

Inheritance:

Bloom syndrome follows an autosomal recessive inheritance pattern. This means that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition. Individuals who carry only one copy of the mutated gene are called carriers. They usually don't show any signs or symptoms of Bloom syndrome.