SNP Shot: Genomic Insights

Proteus syndrome is an uncommon disorder marked by excessive growth of bones, skin, and other tissues. This overgrowth leads to disproportionate body parts, where affected tissues and organs enlarge beyond what's typical. The overgrowth pattern is typically asymmetric, displaying different effects on the body's right and left sides. At birth, infants with Proteus syndrome often show minimal or no symptoms. The overgrowth usually starts to manifest between 6 and 18 months of age and worsens progressively.

The extent and location of overgrowth in Proteus syndrome vary considerably from person to person, potentially impacting nearly any part of the body. Bones of the limbs, skull, and spine are commonly involved. The syndrome can also result in diverse skin growths, notably a cerebriform connective tissue nevus, which is a thick, raised lesion with deep grooves. This unique skin growth typically appears on the soles of the feet and is rarely seen in other conditions. Abnormal growth can also affect blood vessels (vascular tissue) and fat tissue (adipose tissue).

Neurological issues, such as intellectual disability, seizures, and vision impairment, can occur in some individuals with Proteus syndrome. Characteristic facial features may also be present, including a long face, downward-slanting eyes (down-slanting palpebral fissures), a flattened nasal bridge with broad nostrils, and a habitually open mouth. The connection is unclear, but individuals experiencing neurological symptoms are more likely to exhibit these distinct facial traits compared to those without such symptoms. How these signs and symptoms relate to the abnormal growth is not yet understood.

Potential complications associated with Proteus syndrome encompass an elevated risk of developing various non-cancerous (benign) tumors and deep vein thrombosis (DVT), a type of blood clot. DVTs predominantly occur in the deep veins of the legs or arms. Should these clots dislodge and travel to the lungs, they can cause a life-threatening pulmonary embolism. Pulmonary embolism represents a significant cause of mortality among individuals with Proteus syndrome.

Inheritance:

Proteus syndrome arises from AKT1 gene mutations that occur during early embryonic development. Consequently, the condition is not inherited and does not occur as a familial trait.