Pigmented ocular fundus lesions in the inherited gastrointestinal polyposis syndromes and in hereditary nonpolyposis colorectal cancer

Study of diagnostic value of congenital hypertrophy of retinal pigment epithelium in Chinese familial adenomatous polyposis patients

BACKGROUND

Congenital hypertrophy of retinal pigment epithelium (CHRPE) is an important characteristic of familial adenomatous polyposis (FAP) patients. However, more evidence about its sensitivity, specificity, and diagnostic value for FAP is needed to determine whether CHRPE is a reliable marker.

METHODS

Clinical features of FAP patients were investigated using in-person evaluations. Family members of FAP patients were evaluated with an indirect ophthalmoscope to determine whether they had CHRPE. We defined three diagnostic criteria for CHRPE (criteria A, B and C) based on their shape, quantity and size. Those with negative colonoscopy results and gene mutation results were classified as healthy controls.

RESULTS

Of a total of 23 FAP families, 21 families were CHRPE-positive (91.3%). Among those 21 families, 47 individuals had CHRPE, including 33 FAP patients, 9 APC gene mutation carriers, and 5 individuals younger than 18 years who were later confirmed to have FAP. Fifty individuals had no CHRPE (5 FAP patients and 45 individuals without APC gene mutations and colorectal adenoma). The average number of CHRPE lesions per person was 5.81, and CHRPE was located mostly in the posterior pole in the eye fundus; 76.7% of individuals had CHRPE in both eyes. The sensitivity of the three CHRPE criteria ranged from 78.8 to 90.4%, with the highest sensitivity found for criterion A (90.4%), which had a specificity of 100% for healthy controls and sporadic colorectal cancer patients.

CONCLUSION

CHRPE has vital diagnostic and screening value because of its high sensitivity for discovering FAP and APC gene mutation carriers.

Torpedo-like lesions in the ocular fundi of Gardner syndrome: hiding in plain view

Background: The coexistence of fundus torpedoes and Gardner syndrome was initially reported in 1989 and 1992 by Gass and Roseman. Gardner syndrome is a dominantly inherited disease characterized by a multitude of potentially lethal gastrointestinal polyps. Over the ensuing quarter century, several publications demonstrated uncommon, but easily recognized, fundus lesions called Torpedo Maculopathy in apparently normal individuals. These fundus abnormalities were thought to be single and isolated without systemic associations. During the same period of time, a variety of nonspecific fundus abnormalities were described in Gardner syndrome, which, in retrospect, included highly specific lesions that closely resembled macular torpedoes and sometimes were indistinguishable from them.Patient and methods: We now report a confirmed case of Gardner syndrome with numerous fundus torpedoes, and carefully analyze the voluminous literature of both Gardner syndrome and Torpedo Maculopathy.Results: We demonstrate shared features of the fundus lesions in both diseases, and hypothesize that they may have genetic as well as ophthalmoscopic similarities in common.Conclusions: We therefore recommend that individuals with classic isolated torpedoes undergo evaluations for mutations in the Gardner gene (Adenomatous polyposis coli) and for the presence of gastrointestinal polyps and other systemic features of Gardner syndrome. We also suggest that apparently normal individuals, who are genetically related to patients with known classic torpedoes, undergo inspection of their fundi for the possible presence of characteristic lesions.

[Mandibular osteoma in a case of Gardner's syndrome]

Gardner's syndrome is characterized by the triad of intestinal polyposis accompanied by multiple hard- and soft-tissue tumors. Untreated, all patients will develop gastrointestinal cancer by the age of 40. Although incurable, progression can be prevented by close monitoring and prophylactic colectomy to prevent malignancy. Multiple osteomas of the head and jaw bones are common extraintestinal manifestations of Gardner's syndrome and can be helpful in the diagnostic work-up. The disease pattern should be known to the treating physician, since extraintestinal manifestations usually occur long before intestinal polyposis and early diagnosis is critical for the prognosis.

Gardner's syndrome: Genetic testing and colonoscopy are indicated in adolescents and young adults with cranial osteomas: A case report

We present a case of a 25-year-old female with diagnosed familial adenomatous polyposis and elevated carcinoembryonic antigen with negative family history. The suspicion of Gardner's syndrome was raised because extirpation of an osteoma of the left temporo-occipital region was made 10 years ago. Restorative procto-colectomy and ileal pouch anal anastomosis was made but histology delineated adenocarcinoma of the rectum (Dukes C stage). We conclude that cranial osteomas often precede gastrointestinal manifestations of familial adenomatous polyposis or Gardner's syndrome and such patients should be evaluated with genetic testing followed by colonoscopy if results are positive to prevent the development of colorectal carcinoma. If the diagnosis is positive all family members should be evaluated for familial adenomatous polyposis.

Familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal-dominant colorectal cancer syndrome, caused by a germline mutation in the adenomatous polyposis coli (APC) gene, on chromosome 5q21. It is characterized by hundreds of adenomatous colorectal polyps, with an almost inevitable progression to colorectal cancer at an average age of 35 to 40 yr. Associated features include upper gastrointestinal tract polyps, congenital hypertrophy of the retinal pigment epithelium, desmoid tumors, and other extracolonic malignancies. Gardner syndrome is more of a historical subdivision of FAP, characterized by osteomas, dental anomalies, epidermal cysts, and soft tissue tumors. Other specified variants include Turcot syndrome (associated with central nervous system malignancies) and hereditary desmoid disease. Several genotype-phenotype correlations have been observed. Attenuated FAP is a phenotypically distinct entity, presenting with fewer than 100 adenomas. Multiple colorectal adenomas can also be caused by mutations in the human MutY homologue (MYH) gene, in an autosomal recessive condition referred to as MYH associated polyposis (MAP). Endoscopic screening of FAP probands and relatives is advocated as early as the ages of 10-12 yr, with the objective of reducing the occurrence of colorectal cancer. Colectomy remains the optimal prophylactic treatment, while the choice of procedure (subtotal vs proctocolectomy) is still controversial. Along with identifying better chemopreventive agents, optimizing screening of extracolonic cancers and applying new radiological and endoscopic technology to the diagnosis and management of extracolonic features are the major challenges for the future.

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.

Non-cancerous ophthalmic clues to non-ocular cancer

This survey reviews selected medical disorders in which the ophthalmologist has a unique opportunity of anticipating the existence of asymptomatic, life-threatening disease simply by recognizing that certain benign conditions involving the eye or adnexa represent clues to occult non-ocular cancer and other neoplasias. Having knowledge that these clues are associated with specific types of neoplasia, the ophthalmologist can then initiate a goal-directed oncologic investigation designed to identify the underlying neoplasm with the hope of providing potentially life-saving therapy. The survey is organized to feature each clue separately. The clinical characteristics of the clue are described and illustrated with color photographs when possible. A discussion reviews associated malignancies and other important medical features. The survey begins with clues expressed anteriorly in the lids, progressively reviewing those clues located more posteriorly, concluding with clues involving the retinal pigment epithelium and choroid.

Ophthalmic and genetic screening in pedigrees with familial adenomatous polyposis

PURPOSE

To study the possible association between ophthalmic findings, genetic status, and clinical course of the disease in Austrian pedigrees with familial adenomatous polyposis (FAP).

METHODS

Thirty-nine members of 16 consecutive FAP families with 20 affected patients and 19 relatives with a 50% a priori risk to develop the disease were examined ophthalmologically. The intestinal status of all persons was established by colonoscopy. Direct or indirect molecular genetic analysis, or both, was possible in eight of the 16 FAP families.

RESULTS

Congenital hypertrophy of the retinal pigment epithelium (CHRPE) was discovered in 15 (75%) of the 20 persons affected by familial adenomatous polyposis. Five (25%) of the patients with an established FAP were CHRPE-negative. Four of the 19 at-risk individuals were CHRPE-positive. According to DNA analysis, five of the 19 at-risk relatives had a high risk to develop a manifest disease. The ophthalmoscopic tests were in complete agreement with the molecular risk estimation. Furthermore, the combined results of endoscopy and ophthalmoscopy suggested a relationship between a positive CHRPE status and the severity of FAP.

CONCLUSIONS

Ophthalmic examinations facilitate predictive diagnosis in FAP patients and first-degree relatives, permitting a noninvasive, highly reliable risk assessment. When present, CHRPE lesions are a reliable clinical marker for FAP in CHRPE-positive families. In CHRPE negative families, negative ophthalmic examinations are of no predictive value. The CHRPE status can add information about the location of the genetic mutation. The combination of an ophthalmic examination with DNA analysis and endoscopy improves the risk assessment of FAP carriers.

Diagnostic value of fundus examination in familial adenomatous polyposis

BACKGROUND

Multiple, bilateral lesions of congenital hypertrophy of the retinal pigment epithelium (CHRPE) have been described in patients suffering from familial adenomatous polyposis (FAP) since 1980. This study aimed to determine a reliable diagnostic criterion, based on the size and number of retinal CHRPE lesions, allowing the screening of patient carriers of the gene responsible for FAP.

METHODS

32 control subjects and 144 patients belonging to 85 FAP families were studied, divided into 124 carriers of the genetic alteration and 20 non-carriers.

RESULTS

In carriers of the deleted gene, multiple, bilateral retinal lesions were consistently observed. Lesion situation, size, shape, and degree of pigmentation were variable however. A positive criterion for FAP was defined as the presence of at least four lesions whatever their size, or at least two lesions one of which is large. This criterion showed a high sensitivity (0.68) and a maximal specificity (1). Within each family, the retinal phenotypic expression was homogeneous. CHRPE lesions were observed in two thirds of the FAP families and absent from the remaining third.

CONCLUSION

By using this new positive diagnostic criterion, fundus examination allows early detection of those children carrying the gene responsible for FAP in families positive at ocular examination.

Pigmented ocular fundus lesions and APC mutations in familial adenomatous polyposis

BACKGROUND

Familial adenomatous polyposis (FAP) results from a germline mutation in the adenomatous polyposis coli (APC) gene on chromosome 5q21. The extracolonic manifestations of FAP include pigmented ocular fundus lesions (POFLS), cutaneous cysts, osteomas, occult radio-opaque jaw lesions, odontomas, desmoids, and extracolonic cancers. POFLS are present at birth in about 80% of patients with FAP and are excellent clinical congenital markers for the disease. We studied the distribution of POFLS by number and APC mutation in families of the Johns Hopkins Polyposis Registry.

MATERIALS AND METHODS

Of the 51 families with FAP, 42 (82%) had an identifiable APC mutation. We correlated the presence/absence and distribution by number of POFLS with the type and location of the mutation in the APC gene in 21 families where an ocular examination had been performed in at least one affected member, and where a systematic search for mutations in the APC gene had been undertaken. Families were considered POFL-positive if the average number of lesions per patient was three or more, or if at least one family member had three or more lesions.

RESULTS

Fifteen of the 21 families (71.4%) were POFL-positive. Mutations of the APC gene were detected in 15 of the 21 families. Of these, 12 (80%) were POFL-positive. Families with mutations at condons 215 (exon 5) and 302 (exon 8) were POFL-negative. Families with mutations at condons 541, 625, 1055, 1059, 1061, 1230, 1309, 1465, and 1546 (exons 12-15) were POFL-positive. One patient with a mutation at codon 2621 (exon 15) had no POFLS.

CONCLUSIONS

Mutations in exons 1-8 and the distal portion of exon 15 of the APC gene are associated with a POFL-negative phenotype, while those in exons 10 to the proximal portion of exon I5 are generally associated with a POFL-positive

Congenital hypertrophy of the retinal pigment epithelium (CHRPE) and familial adenomatous polyposis (FAP)

Familial adenomatous polyposis (FAP) is a genetically transmitted disease affecting the colon. It is characterized by the presence of several (at least 100) adenomatous polyps, each able to develop into carcinomas, and by other extra-colonic signs such as skin and bone lesions. Within the framework of research studies to identify phenotyphic markers for early detection of subjects at risk within a family affected by FAP, attention has recently been paid to congenital hypertrophy of the retinal pigment ephitelium (CHRPE). With the aim of evaluating the relationship between FAP and CHRPE, 36 members of 7 FAP families were examined. We found that 43.75% of the subjects presenting CHRPE areas were also affected by FAP, whereas 58.33% of patients affected by FAP had CHRPE. Our findings indicated a lower incidence of CHRPE in FAP patients, compared to other studies reported so far. Moreover, in a control group of 160 healthy individuals we found a CHRPE prevalence of 5.5%.

Familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant condition resulting in the development of more than 100 adenomatous polyps in the large bowel. In addition, a number of extracolonic manifestations of the condition may occur. Recently, increasing knowledge relating to the extracolonic abnormalities, and localization and sequencing of the gene for FAP, have had important implications for screening and long-term follow-up of those affected. In this review the natural history of the disease and the extracolonic manifestations associated with it are considered. Surgical management and advances in understanding at a molecular level are discussed, as well as the problems relating to screening for FAP and the implications of the new knowledge.

Congenital hypertrophy of the retinal pigment epithelium and mandibular osteomata as markers in familial colorectal cancer

Congenital hypertrophy of the retinal pigment epithelium (CHRPE) and multiple mandibular osteomata are markers of familial adenomatous polyposis (FAP). We have assessed their prevalence in non-polyposis familial colorectal neoplasia. Multiple mandibular osteomata were present in 1/29 (3%) patients with familial colorectal neoplasia. CHRPE was present in 11/33 (33%) patients with familial colorectal neoplasia compared with 3/36 (8%) with sporadic disease (P = 0.01) and 4/32 (12.5%) control subjects (P = 0.04). Seven patients with familial colorectal neoplasia had multiple areas of CHRPE compared with one with sporadic disease (P = 0.02) and one control subject (P = 0.02). There was no obvious correlation between calculated familial colorectal cancer risk and the presence of multiple areas of CHRPE. A proportion of patients with familial colorectal cancer have a marker found in FAP and may therefore have a constitutional genetic defect, at least in part responsible for their cancer, making them an interesting group for genetic study. Ophthalmoscopy may contribute to risk assessment in familial colorectal cancer.

The role of congenital hypertrophy of the retinal pigment epithelium in screening for familial adenomatous polyposis

Retinal examination by indirect ophthalmoscopy was performed on seventy members from 20 kindreds demonstrating the clinical manifestations of familial adenomatous polyposis and forty controls. Thirty-four of 43 affected patients manifested CHRPE lesions compared with 2 of 27 at risk and 2 of 40 controls giving a sensitivity of 79% and specificity of 95% based on the control group. The difference between the affected and at risk groups was significant (Chi-squared = 34.098, 1 df, P = 0.001). The low sensitivity and variation in incidence of CHRPE in FAP patients and general population documented in the world literature prevent its use as a sole marker for the condition. With advances in knowledge of the disease at a molecular level it is now possible to alter risks for families by DNA analysis. There remain a number of patients in whom such techniques do not significantly alter risks. In these families by combining the results of DNA analysis, sigmoidoscopy and retinal examination it may be possible to alter risks by a significant degree. Retinal examination should be reserved for those families in whom risks cannot be altered sufficiently by DNA analysis alone.

Restriction of ocular fundus lesions to a specific subgroup of APC mutations in adenomatous polyposis coli patients

In humans, alteration of the tumor suppressor gene, APC, causes adenomatous polyposis coli, a condition causing predisposition to colorectal cancer. The syndrome inconsistently associates characteristic patches of congenital hypertrophy of the retinal pigment epithelium (CHRPE). Ocular examination revealed that patients expressing CHRPE tend to cluster within specific families. The exact APC mutation was identified in 42 unrelated patients. In all cases these mutations were predicted to lead to the synthesis of a truncated protein. The extent of CHRPE was found to be dependent on the position of the mutation along the coding sequence. CHRPE lesions are almost always absent if the mutation occurs before exon 9, but are systematically present if it occurs after this exon. Thus, the range of phenotypic expression observed among affected patients may result in part from different allelic manifestations of APC mutations.

Assessment of the value of congenital hypertrophy of the retinal pigment epithelium as an ocular marker for familial adenomatous polyposis coli

The presence of bilateral, multiple patches of congenital hypertrophy of the retinal pigment epithelium (CHRPE) is cited as an early phenotypic marker of the familial adenomatous polyposis coli (FAPC) gene. However, the degree of concordance between CHRPE and the presence of familial adenomatous polyposis (FAP) has not been adequately assessed in individual families. We studied the eyes of 28 members of a single kindred spanning three generations with FAPC; 14 were affected and 14 unaffected but 'at risk'. Six affected and 8 unaffected at risk individuals possessed a total of 34 retinal lesions, 17 in each group. Two affected individuals and 1 at risk individual had the classical pattern of CHRPE associated with FAPC. The sensitivity of CHRPE as an ocular marker for FAPC in this kindred was 14.2%. Our findings have implications for the use of CHRPE for the presymptomatic screening of family members at risk of FAPC. Therefore, ocular examination should not replace colonoscopic screening in an individual at risk of FAPC.

Histopathologic findings in congenital grouped pigmentation of the retina

BACKGROUND

Congenital grouped pigmentation of the retina is a condition characterized by multiple, well-circumscribed, flat, pigmented fundus lesions clustered in a fashion resembling "bear tracks."

METHODS

Light and electron microscopy was used to study these lesions in an eye of a 2-year-old boy. The eye was enucleated for retinoblastoma.

RESULTS

Similar to the classic, solitary, congenital hypertrophy of the retinal pigment epithelium (CHRPE), the involved RPE cells contained an increased number of large pigment granules. Unlike CHRPE, most pigment granules retained the normal ellipsoidal shape. In addition, hypertrophy and hyperplasia of the RPE cells were not significant features by light and electron microscopy.

CONCLUSION

Although the lesions in this case superficially resembled CHRPE by light microscopy, ultrastructural differences were identified.

Cutaneous markers of internal malignancy. I. Malignant involvement of the skin and the genodermatoses

Cutaneous findings often reflect the presence and course of an internal disease. Recognition of external clues is important to facilitate both early diagnosis and prompt treatment of the internal disorder. Early recognition is especially valuable in a patient with an internal malignant disease because intervention may significantly affect survival. In this two-part series, we review the spectrum of cutaneous markers of internal malignancy. Part I focuses on malignant involvement of the skin caused by either direct extension or metastases and the genodermatoses with malignant potential. Part II will be devoted to the paraneoplastic skin manifestations of internal malignancy as well as environmental carcinogens that produce cutaneous features. We also discuss some proposed but controversial associations between skin disease and internal malignancy.

Lack of association among typical congenital hypertrophy of the retinal pigment epithelium, adenomatous polyposis, and Gardner syndrome

BACKGROUND

It has been recently documented that multiple bilateral pigmented lesions at the level of the retinal pigment epithelium may be an indicator of patients with familial adenomatous polyposis who are prone to develop intestinal cancer, particularly if there is a positive family history of these intestinal disorders. Although atypical, such lesions have been called congenital hypertrophy of the retinal pigment epithelium (CHRPE). This study was undertaken to determine whether the typical lesions of CHRPE, seen frequently by ophthalmologists, also were indicators of familial adenomatous polyposis.

METHODS

Review of charts and follow-up studies were performed on all patients diagnosed and coded as having solitary CHRPE or its multifocal variant (congenital grouped pigmentation; bear tracks). Patients and their physicians were contacted by telephone to complete a detailed questionnaire designed to detect signs or symptoms of familial adenomatous polyposis or Gardner syndrome among these patients with CHRPE and their relatives.

RESULTS

Of the 132 patients with previously diagnosed CHRPE, there were none with familial adenomatous polyposis, Gardner syndrome, or intestinal cancer, and only one patient had a history of intestinal polyps. Among more than 2000 of their blood relatives, only 20 had intestinal polyposis or colonic cancer (1%). This is much lower than would be expected from a survey of patients with the typical fundus lesions seen with familial adenomatous polyposis.

CONCLUSIONS

It appears that solitary CHRPE and congenital grouped pigmentation differ clinically from the multiple pigmented lesions seen with familial adenomatous polyposis and that patients with these conditions, as well as their relatives, are not at a greater risk of developing intestinal cancer.

Congenital hypertrophy of retinal pigment epithelium in patients with colonic polyps associated with cancer family syndrome

Congenital hypertrophy of retinal pigment epithelium (CHRPE) has been shown to be a frequent extracolonic manifestation of adenomatous polyposis coli (APC). The presence of CHRPE in patients with adenomatous polyps from families with cancer family syndrome suggests possible involvement of the APC gene locus in syndromes associated with less florid polyp formation than seen in APC. It also emphasises that caution must be exercised in using the presence of CHRPE clinically as a marker for APC in isolated at-risk individuals.

Incidence and significance of congenital hypertrophy of the retinal pigment epithelium (CHRPE) in familial adenomatous polyposis coli (FAPC)

As part of a population based study of familial colorectal cancer 33 affected patients with familial adenomatous polyposis coli (FAPC) and 33 relatives, at 50% risk of inheriting FAPC, from 24 kindreds, were identified and examined. Fourteen of the affected patients had extracolonic manifestations of the FAPC gene. Twenty-five of the 33 affected patients had one or more areas of congenital hypertrophy of the retinal pigment epithelium (CHRPE) and 20 had more than three CHRPEs, all having bilateral lesions. There were significant interfamilial differences in the ocular findings. Because of this interfamilial difference in the predisposition to develop CHRPEs it is important to establish the CHRPE status of individual FAPC families before the results of ophthalmoscopy can be used to predict the carrier status of at risk relatives.

Retinal pigment epithelium lesions as a biomarker of disease in patients with familial adenomatous polyposis. A follow-up report

BACKGROUND

The sensitivity of retinal pigment epithelium (RPE) lesions as a predictive congenital marker for the development of familial adenomatous polyposis (FAP) is evaluated.

METHODS

In a prospective study, 34 patients at 50% risk of inheriting FAP were examined. Based on the presence or absence of four or more RPE lesions, patients were categorized as those who had inherited or those who lacked the FAP genes. All patients received dilated fundus examinations with binocular indirect ophthalmoscopy and all RPE lesions were documented with fundus photography. All patients underwent annual sigmoidoscopy to determine the presence or absence of polyps.

RESULTS

A 3-year follow-up analysis showed that 8 of 14 patients who were positive for RPE lesions later developed polyps. Of the 20 patients considered negative for FAP based on normal fundus examination, none has developed polyps.

CONCLUSION

The authors urge all patient at risk of inheriting FAP to undergo dilated fundus examination with binocular indirect ophthalmoscopy and wide-angle fundus photography at the earliest age possible. All patients with 4 or more RPE lesions should undergo annual sigmoidoscopic examinations beginning before 10 years of age.

Overview of screening and management of familial adenomatous polyposis

The rarity of familial adenomatous polyposis (FAP) means that many clinicians may be unaware of the major advances that have taken place in screening for the condition over the past five years. This review is not only to document the current scene but also to give details of those involved in establishing registries throughout the country. FAP is a hereditary disorder which carries with it almost a 100% risk of colorectal cancer. The aim of screening is to detect gene carriers before they present with symptoms attributable to colonic polyps. In this way the incidence of colorectal cancer can be greatly reduced. The use of gene probes to identify patients with FAP is in its infancy but in selected pedigrees gene carriers can be identified using a venous blood sample. The recognition that congenital hypertrophy of the retinal pigment epithelium is an extracolonic manifestation of FAP in most pedigrees allows non-invasive ophthalmological screening of relatives at risk. The combination of these new screening methods with an effective regional registry for FAP can increase the number of patients detected by screening rather than by symptoms. This facilitates appropriate prophylactic surgery and reduces mortality related to colorectal cancer.

The UK Northern region genetic register for familial adenomatous polyposis coli: use of age of onset, congenital hypertrophy of the retinal pigment epithelium, and DNA markers in risk calculations

A polyposis register has been established in the Northern Region of England. A total of 48 families with 71 living affected subjects has been identified during the first three years of operation, a prevalence of 2.29 x 10(-5). Indirect ophthalmoscopy identifies the majority of gene carriers by showing multiple areas of congenital hypertrophy of the retinal pigment epithelium (CHRPE). The absence of this sign in families limits its value where a relative with CHRPE has not been identified. Combining eye examination with data on age of onset and linked DNA markers is highly effective in carrier exclusion; 38% of 528 first, second, and third degree relatives had their carrier risk reduced to less than 1 in 1000. Even with such assurance many subjects will request continued bowel screening at a reduced frequency. Little interest has been shown in prenatal diagnosis. The principal value of a genetic register with domiciliary nurse visiting is the reduction in early mortality among unrecognised gene carriers.

Ocular findings in Turcot syndrome (glioma-polyposis)

Turcot syndrome is a hereditary condition characterized by multiple, adenomatous gastrointestinal polyps associated with neuroepithelial tumors of the central nervous system. The authors examined a patient with Turcot syndrome who had multiple regions of congenital hypertrophy of the retinal pigment epithelium (CHRPE) with areas of surrounding hypopigmentation in the fundi of both eyes. Multiple, bilateral patches of CHRPE have been reported in patients with familial adenomatous polyposis and Gardner syndrome. This finding is thought to be a sensitive and specific clinical marker for these conditions and useful for predicting the presence and development of colorectal polyposis. Our findings provide further evidence that familial adenomatous polyposis, Gardner syndrome, and Turcot syndrome may be related conditions representing the variable phenotypic expression of a single, autosomal dominant genetic disorder. Children and young adults with multiple patches of CHRPE and a family history of adenomatous polyposis may be at increased risk for the development of central nervous system tumors as well as gastrointestinal polyps.

Predictive value of congenital hypertrophy of the retinal pigment epithelium as a clinical marker for familial adenomatous polyposis

One hundred forty-eight members of 53 kindreds with familial adenomatous polyposis (FAP) were examined for congenital hypertrophy of the retinal pigment epithelium (CHRPE) and extracolonic manifestations (ECM) to assess the value of CHRPE as a predictive marker for FAP. Based on eye examination results, the families were divided into 2 groups. In a first group of 34 families, all 61 members diagnosed as having polyps and 13 of the 33 patients at risk had 4 or more lesions distributed in both eyes. By contrast, in a second group of 18 families, all 32 polyposis patients and all 18 members at risk had less than 4 lesions. Extra-colonic manifestations were present in 26 of 34 families in the first group and in 11 of 18 families in the second group. Data on one family with ambiguous ancestry were reviewed separately. The existence of 4 or more CHRPE lesions distributed in both eyes seems to be a congenital marker for FAP, present in 65.4 percent of families. When present in a family: 1) it is found in all diagnosed patients in that family, 2) can therefore be considered predictive for the development of polyps in other family members who carry the trait, and 3) if confirmed by longer follow-up, may possibly preclude members without the trait from further evaluation and surveillance.

A clinicopathologic study of the eyes in familial adenomatous polyposis with extracolonic manifestations (Gardner's syndrome)

The eyes of a 51-year-old woman with familial adenomatous polyposis and extracolonic manifestations (Gardner's syndrome) were obtained postmortem and studied by light microscopy and by transmission and scanning electron microscopy. We found a generalized abnormality in melanogenesis of the retinal pigment epithelium and at least three types of pigmented lesions. The histologic findings in one type of lesion were consistent with congenital hypertrophy of the retinal pigment epithelium or benign pigmented nevus of the retinal pigment epithelium. The other two types of lesion were most consistent with hamartomatous malformations of the retinal pigment epithelium featuring cellular hypertrophy, hyperplasia, and rarely retinal invasion and formation of a minute mushroom-shaped tumor. These histopathologic findings indicate a generalized effect of the familial adenomatous polyposis gene on the retinal pigment epithelium. This oncogene, which is responsible for tumor formation in the gastrointestinal tract, soft tissues, bone, and other locations in patients with familial adenomatous polyposis, also leads to a generalized defect in melanogenesis and focal lesions of the retinal pigment epithelium.

Congenital hypertrophy of the retinal pigment epithelium. Electron microscopic and morphometric observations

Congenital hypertrophy of the retinal pigment epithelium (CHRPE) is a well-circumscribed, flat, pigmented fundus lesion that is stable and generally nonprogressive. Light and electron microscopy and morphometric analysis was used to study a lesion with the clinical characteristics of CHRPE found in an eye enucleated for a posterior segment malignant melanoma. These studies showed that the lesion was composed of tall, maximally pigmented RPE cells that had a density 1.7 times greater than the density of the adjacent normal peripheral RPE. These observations suggested that cellular hyperplasia and hypertrophy may contribute to CHRPE. Ultraviolet fluorescence microscopy showed no autofluorescent granules of lipofuscin in the CHRPE, suggesting that the lesion's constituent cells lack the capacity to phagocytose and digest photoreceptor outer segments. Photoreceptor degeneration in the overlying retina consequent to this functional defect could be responsible for the localized visual field defects that typically occur in patients with CHRPE.

Congenital hypertrophy of the retinal pigment epithelium in familial adenomatous polyposis

One hundred fifty-three members of 56 kindreds with familial adenomatous polyposis (FAP) underwent funduscopic examination for congenital hypertrophy of the retinal pigment epithelium (CHRPE). All patients underwent wide-angle fundus photography to document lesions, proctosigmoidoscopy to document polyps, and examination for extracolonic manifestations. Ninety-seven patients were diagnosed as having FAP and 56 patients were offspring of FAP patients and thus at 50% risk of inheriting the disease. In two thirds of the kindreds, CHRPE could be used as a congenital phenotypic marker to predict the presence or development of polyps. In these kindreds, all patients with diagnosed FAP and 39% of the patients at risk had at least four CHRPE lesions. In one third of the kindreds, CHRPE could not be used as a predictive congenital marker, and in these kindreds all patients had zero to three total lesions of CHRPE. The presence of CHRPE did not correlate with any other extracolonic manifestations. In kindreds without any other extracolonic manifestations, CHRPE can still be present and can be used as a predictive congenital phenotypic marker.

Congenital hypertrophy of retinal pigment epithelium: a sign of familial adenomatous polyposis

Families of people known to have familial adenomatous polyposis are screened for signs of the disease by yearly examination of the bowel. Multiple areas of congenital hypertrophy of the retinal pigment epithelium have been described in patients with familial adenomatous polyposis. To assess the reliability of this marker 40 patients with familial adenomatous polyposis, representing all 25 pedigrees with living affected members in the Northern region's polyposis registry, were examined for hypertrophy of the retinal pigment epithelium. All had multiple lesions, ranging in number from two to over 40. None of the 35 controls had more than two lesions. Ocular examination is valuable for detecting carriers of the gene for familial adenomatous polyposis before their symptoms develop.