Andalusian Registry for Familial Adenomatous Polyposis: Analysis of patients included

Objective: To evaluate the phenotype and genotype charac teristic of patients included in the Andalusian Registry for familial adenomatous polyposis, the genotype/phenotype correlation and the impact of Registry in the frequency of colorectal cancer of re gistered. Material and methods: A descriptive study of 77 patients with FAP belonging to 33 families, included in a centralized database visited by the physicians of the hospitals taking part in the present study, on prior signing of confidentiality letters. All genetic studies were ca rried out in the Immunology Service of our institution. Results: We have included in our study 77 patients of 33 fa milies; 31 probands with a mean age of 32 years (13-51) and 46 relatives at risk with a mean age of 21.8 years (6-55). Genetic study informed in 68/77 with positive result in 92.6%. Ten pro bands showed colorectal cancer (CRC) at the time of diagnosis (32.2%). Only two affected relatives showed CRC at diagnosis (4.3%), a statistically significant difference (p < 0.05). Gastrointes tinal involvement was observed in 30/61 (49%), desmoid tumors in 7/77 (9.1%) and congenital hypertrophy of the retinal pigment epithelium in 23/55 (65.7%). 86.7% of patients with this altera tion showed mutations between codons 454 and 1019, with a statistically significant correlation ((p< 0.05). Conclusions: The registry has facilitated the genetic diagno sis for all affected families disregard their province of origin. It has also improved the screening of affected relatives and has made it possible to take preventive measures immediately, therefore diminishing the incidence of CRC at diagnosis in registered affected relatives. The correlation between congenital hypertrophy of the retinal pigment epithelium with some mutations is the only phe notypic-genotypic correlation with statistical significance.