Congenital hypertrophy of retinal pigment epithelium (CHRPE) in patients with familial adenomatous polyposis (FAP); a polyposis registry experience

Abstract

BackgroundFamilial Adenomatous Polyposis (FAP) is an autosomal dominant condition giving rise to multiple adenomatous polyps in the colon which invariably become malignant by the fourth decade. Congenital hypertrophy of retinal pigment epithelium (CHRPE) is one of its extra intestinal manifestations early in childhood seen, present in 90% of FAP population and is easy to detect.FindingsPatients diagnosed with FAP and at risk first degree family members were screened for CHRPE using a slit lamp and indirect ophthalmoscopy. The retina of 17 diagnosed FAP patients and 13 individuals at risk were examined. The site and size of CHRPE lesions were documented. Thirteen (76%) of 17 FAP patients (male-10, female – 7, median age - 30 years; range 15-55 years) had CHRPE lesions; seven (54%) had bilateral CHRPE lesions and six (46%) had unilateral lesions. A single lesion was detected in 6 (46%) while 7 (54%) patients had multiple lesions. Of 13 at risk individuals (7- male, female-6 ; median age 34; range 16-52 years), one was positive for CHRPE and 12 were free of retinal lesions. The sensitivity of the presence of a CHRPE lesion in association with colonic polyps in FAP was 76%, specificity 92%, positive predictive value 93%, and negative predictive value 75%.ConclusionsThis study found a high sensitivity and specificity for a CHRPE lesion to be associated with colonic polyps of FAP and hence a useful screening method in a burdened health-care system. The method is minimally invasive and simple and would be of particular value in screening children at risk for FAP.

In patients with a positive family history of familial adenomatous polyposis can the condition be diagnosed from the presence of congenital hypertrophy of the retinal pigment epithelium detected via an eye examination: A systematic review

“…20 Tourino et al found statistically significant differences across a range of CHRPE characteristics. 1 Positive predictive values were as follows: 97.72% (CI: 87.97-99.94, P < .05), 20 93% (CI 0.79-1.06), 4 and 64.28% (CI 44.11-80.69). The mean number of lesions was greater in the polyposis group compared to the at-risk group (11.9 vs 2.8, P < .001).…”

“…The following were noted to be associated with the presence of polyposis: three or more lesions (P < .001), lesions bigger than 0.5-disc diameters (P < .05), bilateral disease (P < .001) and mixed lesions (P < .001). 19 Negative predictive values were reported as: 61.90% (CI: 45.63-76.42%, P < .05), 20 75% (CI 0.54-0.96) 4 and 76.19% (CI 52.45-90.88). Reported sensitivities of using CHRPE as a marker/screening tool to detect FAP were: 96.9%, 15 84%, 12 14.2%, 16 72.88% (CI: 59.73-83.63), 20 79%, 13 76% (CI 0.56-0.97) 4 and 78.26% (CI 55.79-91.71).…”

“…1 Cellular differentiation and melanogenesis of the retinal pigment epithelium (RPE) are brought about through the action of the APC gene. 3,4 CHRPE is a retinal pigmented lesion. 2 In Europe its prevalence is estimated to be 1/11 300-37 600.…”

“…2 In Europe its prevalence is estimated to be 1/11 300-37 600. 4,6,7 FAP patients usually require prophylactic surgery and thus diagnosing FAP early is imperative; history, clinical examination, endoscopy and genetic testing are currently used. One percent of colorectal cancers are accounted for by FAP.…”

Familial adenomatous polyposis in China

“…There are specific FAP-associated syndromes reported in China, including Gardner syndrome and Turcot syndrome (51). CHRPE is another characteristic extra-intestinal manifestation in patients with FAP (52). In 1995, Li et al (53) initially reported CHRPE in 6 patients with CFAP, and in 2010, Ding et al (54) detected CHRPE in 22 patients with FAP, suggesting that CHRPE is an indicator of patients at a high risk of FAP.…”