1/117. Familial paragangliomas: the emerging impact of molecular genetics on evaluation and management. HYPOTHESIS: Advancements in molecular genetics has direct impact on the evaluation and management of patients and family members with familial paragangliomas (FP). BACKGROUND: Familial paragangliomas. in contrast to sporadic cases, are commonly multiple, bilateral, and present at an earlier age. Familial tumors are inherited in an autosomal dominant pattern with genomic imprinting of the paternal allele. Mapping studies have identified regions on chromosome 11q as harboring the genetic defect responsible for paraganglioma formation. methods: A multigenerational family with five affected females with head and neck paragangliomas underwent clinical and genetic evaluation. Genetic mapping was performed with microsatellite markers froin chromosome 11q13 and q23. Nonaffected individuals were screened for carrying the affected haplotype. In addition, by using dna obtained from an amniotic fluid sample. in utero screening of a fetus was performed. RESULTS: The most common complaints were hearing loss and neck masses that usually manifested by age 25. Genetic mapping identified loci 11q13 and q23 as sites likely responsible for tumorogenesis. Three unaffected family members, including a fetus, were identified as carriers of the affected haplotype. The genetic findings were used to design a screening protocol for family members at risk for developing glomus tumors. CONCLUSIONS: Genetic screening of unaffected family members can identify individuals harboring the mutated allele. Identification of family members at risk for developing FP by molecular genetic techniques may lead to early detection of head and neck paragangliomas and may directly impact morbidity from glomus tumors and their treatment. ( info) |
2/117. Inherited cancer and the primary care physician. Barriers and strategies. Difficulties faced by primary care physicians as they increase their responsibility for the diagnosis of inherited cancer risk include issues of cognitive strategy, the context of care, and cultural and institutional factors. Charateristics common to many genetic disorders--such as rarity, variability, implications for relatives, and temporal pattern--render our usual cognitive strategies less effective. Constraints of managed care, care teams, and high turnover of panels create a particularly difficult context for the care of people at risk for inherited cancer. Echoes of the eugenics movement, the implications of expanding genetic knowledge, and concerns about discrimination all complicate collaborative clinical decision making. Eight strategies are suggested to cope with these barriers to diagnosis. Primary care physicians also face challenges managing patients identified as at increased risk for inherited cancer. These include confidentiality, coordination and communication. Concerns for protecting the patient's confidentiality can inadvertently leave primary care physicians with partial information. Coordination is complicated when multiple organ systems and individuals are at risk, and knowledgable specialty centers may be distant. communication requires sensitivity and skill in translating complex concepts from molecular biology and statistics into lay terms. Seven strategies are suggested to help with management. ( info) |
3/117. Germline CDKN2A mutation implicated in predisposition to multiple myeloma. Germline mutations of the CDKN2A (p16(INK4A)) tumor suppressor gene predispose patients to melanoma and pancreatic carcinoma. In contrast, mutations of the murine CDKN2A gene predispose BALB/c mice to pristane-induced plasmacytoma. We describe here a family in which a germline mutation of CDKN2A is present in 4 individuals who developed melanoma as well as in a fifth family member who is suffering from multiple myeloma. To determine whether the CDKN2A mutation predisposed the myeloma patient to her disease, we carried out loss of heterozygosity studies on sorted bone marrow from this individual and observed loss of the wild type CDKN2A allele in the malignant plasma cells. We suggest that germline mutations of CDKN2A may predispose individuals to a wider variety of malignancy than has been hitherto reported, but that the expression of these cancers may depend heavily on the genetic background of the patient. (blood. 2000;95:1869-1871) ( info) |
4/117. Neurosurgical implications of carney complex. OBJECT: The authors present their neurosurgical experience with carney complex. carney complex, characterized by spotty skin pigmentation, cardiac myxomas, primary pigmented nodular adrenocortical disease, pituitary tumors, and nerve sheath tumors (NSTs), is a recently described, rare, autosomal-dominant familial syndrome that is relatively unknown to neurosurgeons. neurosurgery is required to treat pituitary adenomas and a rare NST, the psammomatous melanotic schwannoma (PMS), in patients with carney complex. Cushing's syndrome, a common component of the complex, is caused by primary pigmented nodular adrenocortical disease and is not secondary to an adrenocorticotropic hormone-secreting pituitary adenoma. methods: The authors reviewed 14 cases of carney complex, five from the literature and nine from their own experience. Of the 14 pituitary adenomas recognized in association with carney complex, 12 developed growth hormone (GH) hypersecretion (producing gigantism in two patients and acromegaly in 10), and results of immunohistochemical studies in one of the other two were positive for GH. The association of PMSs with carney complex was established in 1990. Of the reported tumors, 28% were associated with spinal nerve sheaths. The spinal tumors occurred in adults (mean age 32 years, range 18-49 years) who presented with pain and radiculopathy. These NSTs may be malignant (10%) and, as with the cardiac myxomas, are associated with significant rates of morbidity and mortality. CONCLUSIONS: Because of the surgical comorbidity associated with cardiac myxoma and/or Cushing's syndrome, recognition of carney complex has important implications for perisurgical patient management and family screening. Study of the genetics of carney complex and of the biological abnormalities associated with the tumors may provide insight into the general pathobiological abnormalities associated with the tumors may provide insight into the general pathobiological features of pituitary adenomas and NSTs. ( info) |
5/117. Removal of a lumbar melanotic schwannoma via the far-lateral approach in a patient with carney complex. Case report. The authors describe a patient with Carney's complex who presented with sciatica due to a lumbar nerve root sheath tumor. A far-lateral approach was used to resect a nonpsammomatous melanotic schwannoma. Neurosurgeons surgically treating peripheral nerve sheath tumors should be aware of the features of carney complex because the extent of the preoperative evaluation and postoperative management of an otherwise routine surgical condition can be significantly affected. ( info) |
6/117. Evidence for a recessive inheritance of Turcot's syndrome caused by compound heterozygous mutations within the PMS2 gene. Turcot's syndrome is a genetic disease characterized by the concurrence of primary brain tumors and colon cancers and/or multiple colorectal adenomas. We report a Turcot family with no parental consanguinity, in which two affected sisters, with no history of tumors in their parents, died of a brain tumor and of a colorectal tumor, respectively, at a very early age. The proband had a severe microsatellite instability (MIN) phenotype in both tumor and normal colon mucosa, and mutations in the TGFbeta-RII and APC genes in the colorectal tumor. We identified two germline mutations within the PMS2 gene: a G deletion (1221delG) in exon 11 and a four-base-pair deletion (2361delCTTC) in exon 14, both of which were inherited from the patient's unaffected parents. These results represent the first evidence that two germline frameshift mutations in PMS2, an MMR gene which is only rarely involved in HNPCC, are not pathogenic per se, but become so when occurring together in a compound heterozygote. The compound heterozygosity for two mutations in the PMS2 gene has implications for the role of protein PMS2 in the mismatch repair mechanism, as well as for the presymptomatic molecular diagnosis of at-risk family members. Furthermore, our data support and enlarge the notion that high dna instability in normal tissues might trigger the development of cancer in this syndrome. ( info) |
7/117. Epithelioid blue nevus: a rare variant of blue nevus not always associated with the carney complex. Epithelioid blue nevus is a rare variant of blue nevus that has been recently described in patients with carney complex. Some of the patients with carney complex have multiple epithelioid blue nevi and a familial history of similar lesions is often recorded. Epithelioid blue nevus consists of an intradermal melanocytic nevus composed of polygonal epithelioid cells laden with melanin. Neoplastic cells show no maturation at the base of the lesion and, in contrast with the usual stromal changes in blue nevi, epithelioid blue nevus exhibits no fibrosis of the dermis. We have studied three cases of epithelioid blue nevus in three patients with no evidence of carney complex. The lesions were solitary and there was no family history of similar lesions. Therefore, epithelioid blue nevus is a distinctive variant of blue nevus that may also appear as a sporadic lesion and is not always associated with carney complex. ( info) |
8/117. Novel germline mutation (300-305delAGTTGA) in the human MSH2 gene in hereditary non-polyposis colorectal cancer (HNPCC). Hereditary non-polyposis colorectal cancer (HNPCC) is a common hereditary syndrome characterized by the high incidence and early onset of colorectal cancer. The majority of the HNPCC families carry germline mutations in either the MSH2 or the MLH1 mismatch repair gene. A 46 year-old female patient whose family history fulfilled the Amsterdam criteria for HNPCC was diagnosed with undifferentiated adenocarcinoma of the transverse colon. Recognizing the Lynch 2 syndrome (the existance of multiple HNPCC related cancers in a pedigree), we used polymerase chain reaction followed by direct sequencing to screen the coding regions of both the MSH2 and the MLH1 genes for germline mutations in dna from the patient. We detected a novel germline mutation (300-305delAGTTGA) in exon 2 of human MSH2. We noted microsatellite instability in four microsatellite loci. immunohistochemistry showed a lack of expression of the MSH2 gene product in the tumor, suggesting that the mutation is a disease-causing mutation. copyright Wiley-Liss, Inc. ( info) |
9/117. Hereditary cancers in children and ethical and psychosocial implications. This article describes the application of genetic testing of children for hereditary cancers and the resultant ethical and psychosocial implications. Basic cancer genetics concepts are reviewed. Specific hereditary cancers that may affect children are described along with case examples and recommendations for nursing practice. ( info) |
10/117. Malignant cylindroma in Brooke-Spiegler syndrome. A 68-year-old female patient presented with a history of gradual appearance of multiple nodules situated predominantly on the scalp and neck, with a few nodules on the trunk. The nodules began to appear at the age of 30. family history revealed that the patient's brother, son, father and grandmother had similar cutaneous lesions. The dominant histopathological pattern was that of a cylindroma. Features of both cylindroma and spiradenoma (spiradenocylindroma) were present within the same lesion in some biopsies. Most lesions on the scalp were skin-colored with a smooth surface. The largest tumors located on the neck were tender and ulcerated. Histopathologically, these tumors had the morphology of a high-grade malignant solid neoplasm with epithelioid features. ( info) |