SNP Shot: Genomic Insights

Peutz-Jeghers syndrome (PJS) is a genetic disorder distinguished by the formation of hamartomatous polyps (non-cancerous growths) in the digestive system, primarily in the stomach and intestines. Individuals with PJS also face a significantly elevated risk of developing various cancers.

A common sign of PJS in children is the presence of small, dark spots on the lips, around and inside the mouth, around the eyes and nose, and near the anus. These spots can also appear on the hands and feet. Typically, they emerge in childhood and tend to fade with age. Furthermore, most individuals with PJS develop numerous polyps in their stomach and intestines, usually during childhood or adolescence. These polyps can lead to health issues like recurring bowel blockages, ongoing bleeding, and abdominal discomfort.

Individuals affected by Peutz-Jeghers syndrome are at a considerably increased risk of developing cancer throughout their lives. The most frequently observed cancers in PJS patients include tumors of the gastrointestinal tract, pancreas, cervix, ovary, and breast.

Inheritance:

Peutz-Jeghers syndrome follows an autosomal dominant inheritance pattern. This means that only one copy of a mutated gene in each cell is enough to raise the likelihood of developing both non-cancerous polyps and cancerous tumors. Approximately half of all PJS cases involve inheriting a mutation in the STK11 gene from a parent who also has the condition. The other half of cases occur in individuals with no family history of PJS. These cases are believed to arise from new (de novo) mutations in the STK11 gene.