Genetic Counselor Practices Involving Pediatric Patients with FAP: an Investigation of their Self-Reported Strategies for Genetic Testing and Hepatoblastoma Screening

Content analysis of Journal of Genetic Counseling research articles: A multi-year perspective

Content analyses of published papers in journals inform readers, editors, and members of the profession about historical publication patterns and how the journal has represented the field. This study is a content analysis of original research papers published in the Journal of Genetic Counseling from January 2011 through December 2017. This is the first study of its kind for the flagship journal of the National Society of Genetic Counseling. Of 794 papers published in the 7-year period, 428 were original research included in the analysis. Content analysis yielded categories reflecting the types of data analyses, genetic counseling practice specialties, characteristics of the study sample, and major topics/issues investigated in each study. There was an overall positive linear trend in the number of articles published during this period (p = .002). Approximately equal percentages of studies used qualitative (34%), quantitative (31%), and mixed (35%) analyses, and these proportions did not vary significantly across volumes (p = .73). Cancer (27%), prenatal (13.3%), and general genetics (12.6%) were the most prevalent specialties represented. The number of studies about prenatal and pediatrics was less, and the number of studies about neurogenetics was greater than would be expected based on the clinical workforce (p<.001). Patients were the most common sample (55.6%). While there was a significant increase in the number of articles with diverse samples (p = .001), the proportion of such articles did not increase over time (p = .86). The most common content areas were genetic counseling practice (16.8%); attitudes, perceptions, and beliefs about genetics services (16.1%); and decision-making (14.5%). In contrast, relatively few studies focused on laboratory genetic counselor, male, gender non-conforming, and adoptee populations. The trends and gaps highlighted in this content analysis can inform future research endeavors.

Familial Adenomatous Polyposis Syndrome: An Update and Review of Extraintestinal Manifestations

CONTEXT.—

Familial adenomatous polyposis (FAP) is a rare genetic disorder with autosomal dominant inheritance, defined by numerous adenomatous polyps, which inevitably progress to colorectal carcinoma unless detected and managed early. Greater than 70% of patients with this syndrome also develop extraintestinal manifestations, such as multiple osteomas, dental abnormalities, and a variety of other lesions located throughout the body. These manifestations have historically been subcategorized as Gardner syndrome, Turcot syndrome, or gastric adenocarcinoma and proximal polyposis of the stomach. Recent studies, however, correlate the severity of gastrointestinal disease and the prominence of extraintestinal findings to specific mutations within the adenomatous polyposis coli gene (APC), supporting a spectrum of disease as opposed to subcategorization. Advances in immunohistochemical and molecular techniques shed new light on the origin, classification, and progression risk of different entities associated with FAP.

OBJECTIVE.—

To provide a comprehensive clinicopathologic review of neoplastic and nonneoplastic entities associated with FAP syndrome, with emphasis on recent developments in immunohistochemical and molecular profiles of extraintestinal manifestations in the thyroid, skin, soft tissue, bone, central nervous system, liver, and pancreas, and the subsequent changes in classification schemes and risk stratification.

DATA SOURCES.—

This review will be based on peer-reviewed literature and the authors' experiences.

CONCLUSIONS.—

In this review we will provide an update on the clinicopathologic manifestations, immunohistochemical profiles, molecular features, and prognosis of entities seen in FAP, with a focus on routine recognition and appropriate workup of extraintestinal manifestations.

Hepatoblastoma in patients with molecularly proven familial adenomatous polyposis: Clinical characteristics and rationale for surveillance screening

Familial adenomatous polyposis (FAP) due to APC mutation is associated with an increased risk of hepatoblastoma. All cases of hepatoblastoma in patients with FAP reported in the literature were reviewed. One hundred and nine patients were identified. Thirty-five patients (of 49 with data) were diagnosed with hepatoblastoma prior to a later diagnosis of FAP (often in association with advanced colorectal carcinoma), emphasizing a need to identify patients earlier with germline APC mutations for early colorectal carcinoma screening. Hepatoblastoma may present at birth, and screening for hepatoblastoma in infancy in families with FAP prior to APC mutation testing results may be warranted.

A novel tissue-based ß-catenin gene and immunohistochemical analysis to exclude familial adenomatous polyposis among children with hepatoblastoma tumors

BACKGROUND

The Wnt/β-catenin pathway plays a central role in the pathogenesis of most hepatoblastomas (HBs), that is, up to 60-80% carry activating CTNNB1 mutations. HBs can however also be the first manifestation of familial adenomatous polyposis (FAP). As this is a severe disease, it is important for the patient and related family members to firmly exclude FAP at an early stage. Current diagnosis largely depends on APC germline mutation detection on genomic DNA, which is associated with 10-20% false-negative results. Here, we establish and validate a tissue-based β-catenin gene and immunohistochemical analysis, which complements germline mutation screening to exclude the diagnosis of FAP among HB patients.

METHODS

Tumor tissues of 18 HB patients, including three FAP cases were subjected to CTNNB1 exon 3 mutational analysis and immunohistochemistry comparing staining patterns for total and exon 3 specific β-catenin antibodies.

RESULTS

Our novel tissue-based method reliably identified all three FAP patients. Their tumors were characterized by a wild-type exon 3 sequence and a comparable nuclear staining for both antibodies. In contrast, the non-FAP tumors carried missense CTNNB1 mutations combined with a clearly reduced staining for the exon 3 antibody, or complete loss of staining in case of lesions with exon 3 deletions.

CONCLUSION

We have successfully established and validated a novel ß-catenin gene and immunohistochemical diagnostic method, which, when combined with routine germline DNA testing, allows the exclusion of the diagnosis of FAP among HB patients.