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S J Marx

Publications and source records attributed to S J Marx.

At least 73 records · Page 4Linked to original sources
PubMed1997

Germline mutations of the MEN1 gene in familial multiple endocrine neoplasia type 1 and related states.

Familial multiple endocrine neoplasia type 1 (FMEN1) is an autosomal dominant trait characterized by tumors of the parathyroids, gastro-intestinal endocrine tissue, anterior pituitary and other tissues. We recently cloned the MEN1 gene and confirmed its identity by finding mutations in FMEN1. We have now extended our mutation analysis to 34 more unrelated FMEN1 probands and to two related states, sporadic MEN1 and familial hyperparathyroidism. There was a high prevalence of heterozygous germline MEN1 mutations in sporadic MEN1 (8/11 cases) and in FMEN1 (47/50 probands). One case of sporadic MEN1 was proven to be a new MEN1 mutation. Eight different mutations were observed more than once in FMEN1. Forty different mutations (32 FMEN1 and eight sporadic MEN1) were distributed across the MEN1 gene. Most predicted loss of function of the encoded menin protein, supporting the prediction that MEN1 is a tumor suppressor gene. No MEN1 germline mutation was found in five probands with familial hyperparathyroidism, suggesting that familial hyperparathyroidism often is caused by mutation in another gene or gene(s).

Adult↗
PubMed1997

A transcript map for the 2.8-Mb region containing the multiple endocrine neoplasia type 1 locus.

Multiple endocrine neoplasia type 1 (MEN 1) is an inherited cancer syndrome in which affected individuals develop multiple parathyroid, enteropancreatic, and pituitary tumors. The locus for MEN1 is tightly linked to the marker PYGM on chromosome 11q13, and linkage analysis places the MEN1 gene within a 2-Mb interval flanked by the markers D11S1883 and D11S449. Loss of heterozygosity studies in MEN 1 and sporadic tumors suggest that the MEN1 gene encodes a tumor suppressor and have helped to narrow the location of the gene to a 600-kb interval between PYGM and D11S449. Focusing on this smaller MEN1 interval, we have identified and mapped 12 transcripts to this 600-kb region. A precise ordered map of 33 transcripts, including 12 genes known to map to this region, was generated for the 2.8-Mb D11S480-D11S913 interval. Fifteen candidate genes (of which 10 were examined exhaustively) were evaluated by Southern blot and/or dideoxy fingerprinting analysis to identify the gene harboring disease-causing mutations.

Chromosome Mapping↗
PubMed1997

Loss of heterozygosity at 11q13: analysis of pituitary tumors, lung carcinoids, lipomas, and other uncommon tumors in subjects with familial multiple endocrine neoplasia type 1.

Loss of heterozygosity (LOH) for polymorphic markers flanking the multiple endocrine neoplasia type 1 (MEN-1) gene in parathyroid and pancreatic islet tumors from subjects with familial MEN-1 (FMEN-1) has been well documented and has led to the hypothesis that the MEN-1 gene functions as a tumor suppressor. To assess the role of the MEN-1 gene in the pathogenesis of tumors less commonly associated with MEN-1, we employed a large number of highly informative polymorphic markers closely linked to the MEN-1 gene to study a series of 13 such tumors from subjects with FMEN-1 for LOH at 11q13. We were able to identify LOH for 1 or more 11q13 markers in 2 of 3 pituitary tumors, 3 lung carcinoids, and 1 of 2 lipomas. In every case studied, the allele lost represented the normal allele inherited from the unaffected parent. No LOH was detected in 3 skin angiofibromas, an esophageal leiomyoma, or a renal angiomyolipoma despite the presence of at least 2 informative markers for each tumor. Our results suggest that, like that for parathyroid and pancreatic islet tumors, the pathogenesis of pituitary tumors, lung carcinoids, and lipomas occurring in subjects with FMEN-1 probably involves loss of the normal tumor suppressor function of the MEN-1 gene. Our inability to detect 11q13 LOH in skin angiofibromas, leiomyoma, and angiomyolipoma from subjects with FMEN-1 is consistent with the possibility that these neoplasms arose independently by a mechanism unrelated to the MEN-1 gene, but a role for the MEN-1 gene in the pathogenesis of these tumors cannot be definitively excluded until the gene itself is identified and evaluated for small intragenic deletions or point mutations in such tumors.

Adult↗
PubMed1997

Multiple facial angiofibromas and collagenomas in patients with multiple endocrine neoplasia type 1.

OBJECTIVES: To evaluate patients with multiple endocrine neoplasia type 1 (MEN 1) for cutaneous manifestations. DESIGN: Survey during a 3-year period. SETTING: The National Institutes of Health, a tertiary referral research hospital in Bethesda Md. PATIENTS: A consecutive sample of 32 individuals with previously diagnosed MEN1 who were not preselected for the presence of skin lesions were examined for cutaneous abnormalities. None of the patients or family members were diagnosed as having tuberous sclerosis. INTERVENTIONS: Lesions were identified by clinical appearance, photographed, and confirmed histologically. MAIN OUTCOME MEASURE: To determine the frequency of skin lesions in patients with MEN1. RESULTS: Multiple facial angiofibromas were observed in 28 (88%) of the patients with MEN1, with 16 patients (50%) having 5 or more. Angiofibromas were clinically and histologically identical to those in individuals with tuberous sclerosis. Collagenomas were observed in 23 patients (72%). Also observed were cafe au lait macules in 12 patients (38%), lipomas in 11 patients (34%), confetti-like hypopigmented macules in 2 patients (6%), and multiple gingival papules in 2 patients (6%). CONCLUSIONS: Multiple angiofibromas, collagenomas, lipomas, confetti-like hypopigmented macules and multiple gingival papules are cutaneous manifestations of MEN1 and should be looked for in both family members of patients with MEN1 and individuals with hyperparathyroidism of other MEN1-associated tumors. Multiple angiofibromas can no longer be considered pathognomonic for tuberous sclerosis. The observation of angiofibromas in individuals without tuberous sclerosis necessitates further biochemical testing for MEN1.

Adolescent↗
PubMed1996

Allelic deletions on chromosome 11q13 in multiple tumors from individual MEN1 patients.

Familial multiple endocrine neoplasia type 1 is an autosomal dominant hereditary disorder characterized by multiple parathyroid, pancreatic, duodenal, and pituitary tumors. The parathyroid tumors may arise as diffuse areas of hyperplasia, whereas the pancreatic and duodenal tumors usually form as discrete nodules. Except for a single report, tumor loss of heterozygosity (LOH) mapping of the putative MEN1 suppressor gene on chromosome 11q13 in the past has been restricted by analysis of a single tumor from individual patients and somatic cellular contamination. For this reason, it has not been possible to analyze the clonality of the emerging MEN1 neoplasms. Furthermore, it has been previously unknown whether the LOH pattern varies between individual MEN1 tumors in a given patient or among tumors of different histological origins within unrelated patients. To address these previous limitations, the present study introduces a refinement in microdissection in which endothelial cells are stained and selectively excluded. Tissue microdissection was applied to study LOH patterns on chromosome 11q13 using 8 polymorphic DNA markers in 44 different MEN1 tumors from parathyroid, pancreas, and duodenum in nine unrelated patients. In addition, X-chromosome inactivation clonal analysis was applied to 16 individual microdissected regions from seven parathyroid glands in three female patients. The LOH rates of parathyroid lesions (100%) and endocrine tumors of the pancreas (83%) were strikingly different from the LOH rate of gastrinomas (21%), suggesting that the mechanism that drives LOH may be influenced by the tissue context. Moreover, combined LOH and X-chromosome inactivation scoring of the same microdissected region revealed that parathyroid MEN1 neoplasms can consist of more than one clone. In this study, the centromeric boundary of the putative MEN1 gene was PYGM. Analysis of differential LOH patterns in multiple microdissected tumors in the same patient constitutes a novel approach to suppressor gene mapping.

Adult↗
PubMed1996

Dideoxyfingerprinting (ddF) analysis of the type X collagen gene (COL10A1) and identification of a novel mutation (S671P) in a kindred with Schmid metaphyseal chondrodysplasia.

Schmid metaphyseal chondrodysplasia (SMCD; MIM 156500) is an autosomal dominant disorder of the skeleton that is manifested in early childhood by short stature, coxa vara, and a waddling gait. Patients with SMCD have mutations in the gene that codes for the alpha-1 chain of collagen X (COL10A1); however, mutation analysis of this gene is hampered by its size. We studied a family with SMCD: the mother, a 36-year-old woman with a height of 149 cm, had mild bilateral coxa vara. Her two sons presented with short stature, bowed legs, and coxa vara in early childhood. DNA was extracted from peripheral lymphocytes from the three patients and subjected to PCR amplification by COL10A1 gene-specific primers. In addition to single-strand conformational polymorphism (SSCP) analysis of the COL10A1 gene, we used a novel method, dideoxy fingerprinting (ddF). The genetic defect in this family was found to be a previously unreported missense mutation (T-to-C transition) at nucleotide 2011. This change resulted in a Ser-to-Pro substitution at position 671 of the carboxy-terminus of the COL10A1 protein. In addition, the two boys, but not the mother, were found to carry a trinucleotide (CCC) deletion at position 2048 of the 3' untranslated region, a polymorphism of the COL10A1 gene. We conclude that ddF can be used in the analysis of the COL10A1 gene along with SSCP. The S671P substitution is novel, but located in the same region with the other reported COL10A1 mutations, confirming type X collagen as the locus for this disease.

Adult↗
PubMed1996

Parathyroid adenomas in the aortopulmonary window.

PURPOSE: To describe localization studies in nine patients with ectopic parathyroid adenomas in the aortopulmonary window. MATERIALS AND METHODS: Nine patients with ectopic parathyroid tissue (eight adenomas, one hyperplastic gland) in the aortopulmonary window were examined with ultrasound (US), computed tomography (CT), magnetic resonance (MR) imaging, and scintigraphy. Diagnostic arteriography (n = 4) and venous sampling (n = 3) were performed in the first four patients; arteriography for the purpose of staining was attempted in the last five patients. RESULTS: The results of CT and MR imaging studies were positive in eight of nine patients (89%) and five of eight patients (63%), respectively. The results of thallium/technetium scintigraphy were negative in three patients scanned (0%), but the results of a repeat study in one patient were positive (33%). Sestamibi scans were positive in six of six patients (100%). Single photon emission CT was performed in all six patients and enabled distinction between adenomas in the aortopulmonary window and those in the thymus. CONCLUSION: Ectopic parathyroid glands in the aortopulmonary window are usually detected at sestamibi scintigraphy, and SPECT is helpful in distinguishing these adenomas from more common adenomas in the anterior mediastinum. CT and MR imaging studies can also enable this distinction, but imaging must extend below the aortic arch.

Adenoma↗
PubMed1995

High cervical intravagal hypercellular parathyroid gland as the etiology of severe persistent primary hyperparathyroidism.

The preoperative localization and operative management of a high cervical intravagal parathyroid adenoma in a young woman with severe persistent primary hyperparathyroidism is presented. The etiology of persistent hyperparathyroidism is most frequently a missed adenoma that is often in an ectopic location; of these, undescended adenomas represent a small but important proportion. If clinical suspicion and preoperative localization procedures suggest an undescended gland, a direct surgical approach using a high cervical incision and a unilateral exploration is often successful.

Adenoma↗
PubMed1995

Technetium-99m-sestamibi imaging before reoperation for primary hyperparathyroidism.

UNLABELLED: Recent studies have reported high sensitivities for parathyroid localization with 99mTc-sestamibi and have been performed using either 123I/99mTc-sestamibi or a double-phase sestamibi scanning technique. These studies have focused primarily on patients undergoing initial surgery. We studied 35 patients prior to reoperative surgery to investigate the relative sensitivities of these two technique sin this patient population. METHODS: Double-phase sestamibi scanning (early and delayed imaging) was performed in all patients. Evaluable 123I/99mTc-sestamibi subtraction studies were also obtained in 25 patients. Results were correlated with surgical findings in 32 patients and with clinical outcome in 3 patients in whom mediastinal lesions were radiographically ablated. RESULTS: Overall, double-phase sestamibi imaging detected 23 of 39 abnormal parathyroid glands (59%), whereas 123I/99mTc-sestamibi detected 19 of 27 (70%). Oblique imaging, delayed imaging and 123I subtraction all contributed to sensitivity, and 123I subtraction also proved useful in patients with partial thyroid suppression. Two patients had lesions visible on the early sestamibi images that were not seen at all on the delayed scans. There were four false-positive findings. CONCLUSION: No significant differences between double-phase sestamibi and 123I/99mTc-sestamibi subtraction scanning were found, although the latter tended to be more sensitive.

Adenoma↗
PubMed1994

Familial hypocalciuric hypercalcemia and neonatal severe hyperparathyroidism. Effects of mutant gene dosage on phenotype.

Neonatal severe hyperparathyroidism is a rare life-threatening disorder characterized by very high serum calcium concentrations (> 15 mg/dl). Many cases have occurred in families with familial hypocalciuric hypercalcemia, a benign condition transmitted as a dominant trait. Among several hypothesized relationships between the two syndromes is the suggestion that neonatal severe hyperparathyroidism is the homozygous form of familial hypocalciuric hypercalcemia. To test this hypothesis, we refined the map location of the gene responsible for familial hypocalciuric hypercalcemia on chromosome 3q. Analyses in 11 families defined marker loci closely linked to the gene responsible for familial hypocalciuric hypercalcemia. These loci were then analyzed in four families with parental consanguinity and offspring with neonatal severe hyperparathyroidism. Each individual who was homozygous for loci that are closely linked to the gene responsible for familial hypocalciuric hypercalcemia had neonatal severe hyperparathyroidism. The calculated odds of linkage between these disorders of > 350,000:1 (lod score = 5.56). We conclude that dosage of the gene defect accounts for these widely disparate clinical phenotypes; a single defective allele causes familial hypocalciuric hypercalcemia, while two defective alleles causes neonatal severe hyperparathyroidism.

Chromosome Mapping↗
PubMed1994

Mapping the gene for hereditary hyperparathyroidism and prolactinoma (MEN1Burin) to chromosome 11q: evidence for a founder effect in patients from Newfoundland.

An autosomal dominant syndrome of prolactinomas, carcinoids, and hyperparathyroidism was described in four Newfoundland kindreds in 1980 and in one kindred from the Pacific Northwest in 1983. Because this syndrome shares many features with multiple endocrine neoplasia type 1, the gene for which maps to proximal chromosome 11q, we performed linkage studies with chromosome 11 markers in prolactinoma families to determine whether the two genes map to the same location. All proximal chromosome 11q markers gave positive LOD scores, and no recombinants were seen with PYGM (LOD score 15.25, recombination fraction .0). All affected individuals from Newfoundland shared the same PYGM allele, providing evidence for a founder effect. The disease in the Pacific Northwest kindred cosegregated with a different PYGM allele.

Base Sequence↗
PubMed1994

Use of preoperative fine-needle aspiration in patients undergoing reoperation for primary hyperparathyroidism.

BACKGROUND: Neck reexploration for primary hyperparathyroidism has a lower success rate and greater morbidity than initial exploration because of scarring and distortion of tissue planes and the possibility of a parathyroid neoplasm located in an ectopic or unusual position. Although the use of standard noninvasive imaging studies for reoperative parathyroid surgical procedure is well accepted, the use of invasive studies to localize parathyroid neoplasms, particularly percutaneous aspiration of potential lesions, is controversial. In this report we analyze the results and morbidity in patients undergoing fine-needle aspiration before neck reexploration. METHODS: From 1982 to 1993, 255 patients underwent reexploration for persistent or recurrent hyperparathyroidism at the National Institutes of Health. Of these 255 patients 42 underwent 44 preoperative fine-needle aspirations by ultrasonography or computed tomography guidance in an attempt to localize a parathyroid neoplasm. The aspirated contents were then analyzed for parathyroid hormone content. RESULTS: Of the 44 aspirations 26 (59%) were true positives with no false positives. Of 18 negative fine-needle aspirations, 11 (25%) were false negatives, and seven (16%) were true negatives. The specificity and sensitivity of percutaneous fine-needle aspiration were 100% and 70%, respectively. CONCLUSIONS: Percutaneous fine-needle aspiration for parathyroid hormone is a safe, well-tolerated technique that is highly specific and allows a directed surgical resection avoiding further invasive workup when the aspirate is positive.

Adult↗
PubMed1994

Localization and operative management of undescended parathyroid adenomas in patients with persistent primary hyperparathyroidism.

BACKGROUND: Between 5% and 10% of patients who undergo cervical exploration for primary hyperparathyroidism will have persistent or recurrent hyperparathyroidism. Many of these patients have parathyroid tumors in unusual locations. One such site of ectopic parathyroid tissue is an undescended parathyroid adenoma at or superior to the carotid bifurcation. We describe our experience with the preoperative localization and surgical management of undescended parathyroid adenomas. METHODS: From 1982 to 1993 a consecutive series of 255 patients have undergone localization studies and surgical exploration for persistent or recurrent hyperparathyroidism at the Clinical Center of the National Institutes of Health. Operative strategy was determined by review of the patient's surgical history, disease reports, and data from localizing studies. Patients with an undescended parathyroid adenoma identified before the operation were examined with a direct approach high in the neck. Patients who did not have definitive preoperative localization were explored with the previous transverse cervical incision. RESULTS: Seventeen undescended parathyroid adenomas were identified in 255 patients. Thirteen (76%) of 17 patients had an undescended parathyroid adenoma precisely localized before the operation and were examined via a limited, oblique incision high in the neck anterior to the sternocleidomastoid muscle. In the 13 patients who had undergone accurate localization before the operation, the median operative time was 75 minutes compared with 235 minutes for four patients who did not have an undescended parathyroid adenoma identified before the operation and were examined via a previous transverse cervical incision. All patients were cured of their hyperparathyroidism. CONCLUSIONS: Undescended parathyroid adenomas were the cause of failed cervical exploration in 17 (7%) of 255 patients. Accurate preoperative localization of these lesions is possible in most cases with a combination of noninvasive and invasive modalities. Successful preoperative localization can convert a prolonged exploration of the neck and mediastinum into a brief, curative procedure with minimal morbidity.

Adenoma↗
PubMed1993

Mutations in the human Ca(2+)-sensing receptor gene cause familial hypocalciuric hypercalcemia and neonatal severe hyperparathyroidism.

We demonstrate that mutations in the human Ca(2+)-sensing receptor gene cause familial hypocalciuric hypercalcemia (FHH) and neonatal severe hyperparathyroidism (NSHPT), two inherited conditions characterized by altered calcium homeostasis. The Ca(2+)-sensing receptor belongs to the superfamily of seven membrane-spanning G protein-coupled receptors. Three nonconservative missense mutations are reported: two occur in the extracellular N-terminal domain of the receptor; the third occurs in the final intracellular loop. One mutated receptor identified in FHH individuals was expressed in X. laevis oocytes. The expressed wild-type receptor elicited large inward currents in response to perfused polyvalent cations; a markedly attenuated response was observed with the mutated protein. We conclude that the mammalian Ca(2+)-sensing receptor "sets" the extracellular Ca2+ level and is defective in individuals with FHH and NSHPT.

Amino Acid Sequence↗
PubMed1993

A pulsed-field gel electrophoresis (PFGE) map of twelve loci on chromosome 11q11-q13.

We report a pulsed-field gel electrophoresis map of 12 loci on proximal human chromosome 11q. Linkage studies have shown that this region of chromosome 11 contains the genes for familial atopic disease (APY) and multiple endocrine neoplasia type I (MEN1) (4). A physical map containing polymorphic loci will aid in the isolation of these disease genes. The map reported here has two noncontiguous groups of loci accounting for 8 of the 12 loci evaluated. One group spans a maximum distance of 1600 kb and includes D11S146, BCL1, PRAD1, INT2, and HSTF1. The other group includes FTH1, C1NH, and COX8. TCN1, PGA, and PYGM did not yield any comigrating fragments and could not be physically linked on this PFGE map. These data enhance previously published physical maps of proximal 11q by refining the localization of and distances between markers in the BCL1 region. Additionally, new information about the locations and physical relationships between FTH1, C1NH, and COX8 is presented.

Autoradiography↗
PubMed1993

Vitamin D-dependency rickets type II: truncated vitamin D receptor in three kindreds.

Fibroblasts from three patients with vitamin D-dependency rickets type II were used to study mutations in the 1,25-dihydroxyvitamin D3 receptor responsible for this hereditary disease. Normal human fibroblasts contain 43 +/- 13 fmol receptor/mg protein as determined by immunoradiometric assay and 22 +/- 3 fmol/mg by ligand binding assay. The fibroblasts from the rachitic patients contained no receptor detectable by either method. The 1,25-(OH)2D receptor cDNA for cells from each kindred was produced from total RNA using reverse transcription and polymerase chain reaction amplification. When these cDNAs were sequenced, it was found that each cell line contained a nucleotide substitution resulting in a stop codon in the coding sequence. The predicted resultant receptor protein is 69 amino acids long in one family, and 148 and 291 amino acids long in two other families. These truncated proteins have little or no 1,25-dihydroxyvitamin D3-binding domain accounting for 1,25-dihydroxyvitamin D resistance.

Base Sequence↗
PubMed1993

Progression of uremic hyperparathyroidism involves allelic loss on chromosome 11.

In occasional cases of secondary hyperparathyroidism, long term stimulation of the parathyroid glands leads from compensatory to autonomous hyperfunction, and thus, hypercalcemia develops. This clinical entity, named tertiary hyperparathyroidism, is possibly due to the formation of an adenoma in one of the hyperplastic glands. Previous studies have shown that parathyroid adenomas may arise with allelic loss on chromosome 11. We tested for allelic loss at several loci on chromosome 11 in 12 enlarged parathyroid glands from 6 uremic patients and found loss of heterozygosity in 2 of the glands from 2 different patients with higher serum calcium levels (11.3 +/- 0.29 vs. 9.8 +/- 0.28 mg/dL; P < 0.004) and, therefore, ascribable to the so-called tertiary hyperparathyroidism. The 2 glands with allelic loss were significantly greater in mass than those without loss (3.42 +/- 0.37 vs. 1.60 +/- 0.54 g; P < 0.001). These data offer new evidence that autonomous parathyroid proliferation in uremic patients can develop through overgrowth by a monoclonal tumor, presumably with inactivation of a tumor suppressor gene(s) on chromosome 11.

Adenoma↗