Value of the congenital hypertrophy of the retinal pigment epithelium in the diagnosis of familial adenomatous polyposis.
BACKGROUND
Several kinds of congenital hypertrophy of the retinal pigment epithelium (CHRPE) have been described in patients with familial adenomatous polyposis (FAP). This study aims to assess which properties of CHRPE better predict FAP and investigate whether a relationship exists between specific CHRPE characteristics and FAP variants.


METHODS
We examined 286 subjects, Group I--patients with FAP plus individuals "at risk"; n = 173; Group II--controls n = 113. Retinal lesions were classified in five types (A-E) and different characteristics (distribution, number, shape, size, pigmentation and site) were evaluated.


RESULTS
The most common lesions in affected subjects were types A-D (83.4%) whilst in the "at risk" and control groups were type E. Greater numbers of lesions and bilateral distribution occurred more frequently among affected subjects than in other participants (p < 0.001). Large lesions with mixed pigmentation were associated with polyposis (p > 0.5). Controls had solitary CHRPE lesions (3.5%) and types C and E lesions (23%). The cumulative sensitivities and specificities of CHRPE were 42 and 97%, respectively. CHRPE was most common among those with classical FAP, but no specific characteristic was associated with any particular FAP variant.


CONCLUSIONS
Pigmented fundal lesions are highly pleomorphic and represent the variable expression of a common genetic defect of growth regulation. No association was found between CHRPE characteristics and specific FAP variants.
Department of Ophthalmology, School of Medicine, Complejo Hospitalario Universitario de Santiago, Santiago de Compostela, Spain. rtourinop@msn.com
Rosario
R
Touriño
Rogelio
R
Conde-Freire
José M
JM
Cabezas-Agrícola
Teresa
T
Rodríguez-Aves
Maria Jesús
MJ
López-Valladares
José L
JL
Otero-Cepeda
Carmen
C
Capeans
D011125:Adenomatous Polyposis Coli / Q000145:classification / Q000175:diagnosis*; D000328:Adult; D005260:Female; D006801:Humans; D006984:Hypertrophy / Q000175:diagnosis; D008297:Male; D010857:Pigment Epithelium of Eye / Q000473:pathology*; D011446:Prospective Studies; D012164:Retinal Diseases / Q000145:classification / Q000175:diagnosis*