Preliminary results of the molecular diagnosis of familial adenomatous polyposis in Cuban families.
OBJECTIVE
Familial adenomatous polyposis (FAP) is an autosomal dominant condition characterized by multiple adenomatous polyps in the colon and rectum that inevitably develop into adenocarcinomas if the patient's colon is not removed in time. To date more than 500 mutations related to the disease have been identified in the APC (adenomatous polyposis coli) gene. The molecular study of FAP families was initially introduced in Cuba with the aim of identifying the asymptomatic carriers of APC gene mutations in each family.


METHODS
We studied 23 individuals from 17 Cuban families who had been diagnosed clinically with FAP. Peripheral DNA was extracted from the index case of each family. Exon 15 of the APC gene was screened for germinal mutations using PCR and DNA heteroduplex.


RESULTS
Three different germinal mutations were identified in the mutational clustering region of APC gene by sequencing analysis in five FAP unrelated families. Three families carry the most frequent mutation in APC in codon 1309, while the other two families carry mutations in codons 1061 and 1192, respectively. Two asymptomatic carriers of one family were detected, and later the disease was confirmed by colonoscopy in a very early stage while six members at risk were found to be negative.


CONCLUSIONS
For the first time in Cuba molecular diagnosis of FAP was performed and the development of colorectal cancer prevented in asymptomatic carriers.
Cruz-Bustillo
Diana
D
National Institute of Gastroenterology, Calle 25 no 503 entre H e I, Havana 10400, Cuba. dcruzb@infomed.sld.cu
Villasana
Luis
L
Llorente
Francisco
F
Casadesús
Damián
D
García
Elsa
E
Syrris
Petros
P
Carter
Nick
N
Guerra
Rosa
R
Llanio
Raimundo
R
D011125:Adenomatous Polyposis Coli / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D003462:Cuba / Q000453:epidemiology; D005192:Family Health; D005260:Female; D017491:Genes, APC; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques; D009367:Neoplasm Staging; D010641:Phenotype; D017354:Point Mutation / Q000235:genetics; D012307:Risk Factors; D012720:Severity of Illness Index
D014408:Biomarkers, Tumor