Familial variation in retinal pigmentation in adenomatous polyposis.
OBJECTIVE
To examine the relationship between familial adenomatous polyposis and retinal pigment epithelial (RPE) pigmentation in affected patients and their first-degree relatives.


METHODS
Retrospective study.


METHODS
Affected families across Canada registered in the Steve Atanas Stavro Familial Gastrointestinal Cancer Registry.


METHODS
A total of 134 subjects aged 10 to 35 years (at high risk for the disease) who had undergone examination of the gut by sigmoidoscopy, colonoscopy with biopsy or resection with biopsy and indirect ophthalmoscopy.


METHODS
Weighted eye score for large and small retinal lesions; family eye pigmentation index (FEPI), calculated from the weighted eye scores for individual affected family members.


RESULTS
Families differed in the number and type of RPE lesions manifest, but affected family members showed similar pigmentation. An FEPI below 3 was uninformative, but with a medium or high FEPI the sensitivity and specificity of the index approached 100%.


CONCLUSIONS
A positive retinal examination signifies a high risk for adenomatous polyposis, whereas a negative retinal examination is uninformative. Current molecular analysis is informative in 95% of families. However, in cases of spontaneous mutation and in patients with no first-degree relatives available or with unknown parenthood, RPE lesions are the most valuable extracolonic manifestation of adenomatous polyposis.
Parker
J A
JA
Department of Ophthalmology, University of Toronto, Ont.
Berk
T
T
Bapat
B V
BV
D011125:Adenomatous Polyposis Coli / Q000175:diagnosis* / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D002170:Canada; D002648:Child; D003113:Colonoscopy; D005189:False Positive Reactions; D005260:Female; D014644:Genetic Variation; D006801:Humans; D006984:Hypertrophy; D008297:Male; D009887:Ophthalmoscopy; D010857:Pigment Epithelium of Eye / Q000473:pathology*; D011237:Predictive Value of Tests; D012042:Registries; D012189:Retrospective Studies; D012680:Sensitivity and Specificity