Colorectal cancers are mostly sporadic; some cases of familial clustering and autosomal dominant conditions are also known to occur. Juvenile polyposis syndrome (JPS) is an autosomal dominant condition caused by the mutation of the SMAD4 or the BMPR1A genes. JPS is characterized by hamartomatous polyps developing in the upper and lower intestine. Contradicting previous studies, many of these polyps can go through malignant transformation.This paper reports the case of a male patient who was continuously treated for juvenile polyposis. During the eighteen years of treatment, more than hundred polyps were endoscopically removed from his gastrointestinal tract. The patient's care was interrupted for eight years due to insufficient compliance. He was subsequently referred to our Department of Gastroenterology in severe clinical condition caused by metastatic colorectal cancer. He died after a short palliative therapy at the age of 31. His first-degree accessible relatives were further examined for juvenile polyposis syndrome. Several gastrointestinal polyps of different histological origin were observed in the deceased patient's brother, who subsequently had to undergo a left lateral hemicolectomy. Genetic analyses revealed mutations of the BMPR1A gene in the clinically affected brother, the brother's daughter, and in the deceased proband's daughter.Indebt genetic analyses helped customize and deliver care to a very specific group of individuals. We were able to identify potential family members on whom preventive care and treatment could be focused and simultaneously prevented unnecessary clinical and invasive procedures on those who were healthy. Furthermore, these analyses helped prevent future unnecessary trauma or distress on the analyzed family.