SNP Shot: Genomic Insights

BAP1 tumor predisposition syndrome is a genetic condition passed down through families that elevates the risk of developing various tumors, both cancerous (malignant) and non-cancerous (benign). The most frequent tumor types are found in the skin, eyes, kidneys, and the mesothelium (the tissue lining the chest, abdomen, and outer surface of internal organs). Individuals with this syndrome may develop single or multiple tumors, and family members with the condition can experience different types of tumors.

Some individuals with BAP1 tumor predisposition syndrome develop atypical Spitz tumors on their skin. They may have multiple, sometimes dozens, of these tumors. While generally considered benign, the potential for these tumors to become cancerous is uncertain. Skin cancers, including cutaneous melanoma and basal cell carcinoma, are also associated with this syndrome.

Uveal melanoma, a type of eye cancer, is the most common cancerous tumor seen in BAP1 tumor predisposition syndrome. Although often without symptoms, some individuals with uveal melanoma may experience blurred vision, floaters or flashes of light, headaches, or a visible dark spot in the eye.

Malignant mesothelioma, a cancer of the mesothelium, is a risk for people with BAP1 tumor predisposition syndrome. When related to this syndrome, malignant mesothelioma commonly affects the peritoneum (the membrane lining the abdomen and covering abdominal organs). Less frequently, it occurs in the pleura (the outer covering of the lungs).

Clear cell renal cell carcinoma, a type of kidney cancer, is also linked to BAP1 tumor predisposition syndrome. Research is ongoing to determine if other cancers are associated with this condition.

Cancers arising in individuals with BAP1 tumor predisposition syndrome tend to occur at a younger age and often exhibit more aggressive behavior compared to cancers in the general population. These cancerous tumors are prone to spreading (metastasizing) to other areas of the body. Generally, affected individuals have a shorter survival time than others with the same cancers not related to the syndrome. However, individuals with malignant mesothelioma associated with BAP1 tumor predisposition syndrome appear to have longer survival rates compared to those with the cancer alone.

Inheritance:

BAP1 tumor predisposition syndrome follows an autosomal dominant inheritance pattern. This means that inheriting just one copy of the altered BAP1 gene increases the risk of developing one or more tumors. In most instances, an affected person has one parent who also has the condition. Individuals inheriting a mutated BAP1 gene have a higher risk of tumor development, but not all carriers of the gene mutation will develop a tumor.