Demographic and phenotypic features of 70 families segregating Barrett's oesophagus and oesophageal adenocarcinoma.

BACKGROUND: Based on reported familial patterns, inheritance of a predisposition of developing Barrett's oesesophagus (BO) and oesophageal adenocarcinoma (OAC) likely follows an autosomal dominant model of most inherited cancer syndromes. oesophagus (BO) and oesophageal adenocarcinoma (OAC) likely follows an autosomal dominant model of most inherited cancer syndromes. AIMS: We analysed the phenotypic features of 70 familial BO/OAC families accrued for the purpose of initiating a linkage study to search for genes that contribute to susceptibility for BO/OAC. METHODS: Families with young or familial BO/OAC were recruited from participating institutions and self-referral from advertisement. RESULTS: A total of 70 families (173 affected and 784 unaffected individuals) were recruited into this study. Mean ages of diagnosis of BO and OAC among males were 50.6 and 57.4 years, respectively; among females, 52.1 and 63.5 years, respectively. The standardised incidence ratio (SIR) of cancers other than OAC or oesophagogastric junctional adenocarcinoma (OGJAC), among probands was 0.71. Seventy one percent of the pedigrees have "typical" structures with less than three affected individuals. Power calculations under realistic model assumptions suggest that if genetic heterogeneity is absent or limited, then DNA collection from members of these pedigrees could enable the identification of a novel candidate susceptibility gene for BO/OAC in a genome scan. CONCLUSIONS: This is the largest series of families with BO/OAC yet reported, features of which are consistent with inherited germline predisposition. Further, the SIR of cancers other than OAC/OGJAC was 0.71 among 70 probands, indicating these individuals were not more likely to develop non-OAC cancers.

Prevalence of SDHB, SDHC, and SDHD germline mutations in clinic patients with head and neck paragangliomas.

BACKGROUND: Paragangliomas are rare and highly heritable tumours of neuroectodermal origin that often develop in the head and neck region. Germline mutations in the mitochondrial complex II genes, SDHB, SDHC, and SDHD, cause hereditary paraganglioma (PGL). METHODS: We assessed the frequency of SDHB, SDHC, and SDHD gene mutations by PCR amplification and sequencing in a set of head and neck paraganglioma patients who were previously managed in two otolaryngology clinics in the USA. RESULTS: Fifty-five subjects were grouped into 10 families and 37 non-familial cases. Five of the non-familial cases had multiple tumours. Germline SDHD mutations were identified in five of 10 (50%) familial and two of 37 ( approximately 5%) non-familial cases. R38X, P81L, H102L, Q109X, and L128fsX134 mutations were identified in the familial cases and P81L was identified in the non-familial cases. Both non-familial cases had multiple tumours. P81L and R38X mutations have previously been reported in other PGL families and P81L was suggested as a founder mutation. Allelic analyses of different chromosomes carrying these mutations did not show common disease haplotypes, strongly suggesting that R38X and P81L are potentially recurrent mutations. Germline SDHB mutations were identified in two of 10 (20%) familial and one of 33 ( approximately 3%) non-familial cases. P131R and M71fsX80 were identified in the familial cases and Q59X was identified in the one non-familial case. The non-familial case had a solitary tumour. No mutations could be identified in the SDHC gene in the remaining four families and 20 sporadic cases. CONCLUSIONS: Mutations in SDHD are the leading cause of head and neck paragangliomas in this clinic patient series. SDHD and SDHB mutations account for 70% of familial cases and approximately 8% of non-familial cases. These results also suggest that the commonness of the SDHD P81L mutation in North America is the result of both a founder effect and recurrent mutations.

Proportion of heritable paraganglioma cases and associated clinical characteristics.

OBJECTIVE/HYPOTHESIS: To determine the heritable proportion of paraganglioma (PGL) and identify clinical features associated with heritable PGL. STUDY DESIGN: Patients diagnosed with head and neck PGLs, identified retrospectively through clinical otolaryngology practices and/or participation in previous PGL research studies, were given a medical and family history questionnaire. METHODS: Questionnaire information was used to classify participants as having "heritable" or "non-heritable" cases of PGL. Classification of the participants identified through otolaryngology clinics was used to estimate the heritable proportion of PGL. Statistical analysis was performed to identify significant differences in the clinical characteristics of the heritable versus non-heritable groups. RESULTS: Among the otolaryngology clinic population, 35% were classified as having heritable PGL. Individuals with heritable PGL were younger on average than those with non-heritable PGL. The majority of non-heritable participants were female, but there was an equal gender ratio among the heritable participants. Individuals diagnosed with a carotid body tumor (CBT) were 5.8 times more likely to be classified as heritable than those diagnosed with PGL at other anatomic locations. CONCLUSIONS: Approximately 35% of individuals who present to an otolaryngologist with a head and neck PGL have inherited a predisposition for this growth. Among individuals diagnosed with head and neck PGL, those diagnosed with CBT are 5.8 times more likely to have an inherited predisposition than those diagnosed with PGL at other anatomic locations.