An odontogenic keratocyst (OKC) is a benign cystic lesion of the jaws that occurs sporadically or in association with nevoid basal cell carcinoma syndrome (NBCCS). Recently, the gene for NBCCS was cloned and shown to be the human homologue of the Drosophila segment polarity gene Patched (PTCH), a tumor suppressor gene. The PTCH gene encodes a transmembrane protein that acts in opposition to the Hedgehog signaling protein, controlling cell fates, patterning, and growth in numerous tissues, including tooth. We investigated three cases of sporadic odontogenic keratocysts and three other cases associated with NBCCS, looking for mutations of the PTCH gene. Non-radioactive single-strand conformational polymorphism and direct sequencing of PCR products revealed a deletion of 5 base pairs (bp) in exon 3 (518delAAGCG) in one sporadic cyst as well as mutations in two cysts associated with NBCCS, a nonsense (C2760A) and a missense (G3499A) alteration. This report is the first to describe a somatic mutation of PTCH in sporadic odontogenic keratocysts as well as two novel mutations in cysts associated with NBCCS, indicating a similar pathogenesis in a subset of sporadic keratocysts.

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This study describes a novel mutation of the cathepsin C gene in a Brazilian kindred with Papillon-Lefèvre syndrome.

Central giant cell lesion (CGCL) is a reactive bone lesion that occurs mainly in the mandible, characterized by the multinucleated osteoclast-like giant cells in a background of oval to spindle-shaped mononuclear cells. The etiology is unknown and occurs more commonly in young adults. Cherubism, a rare disease found predominantly in females has histologic characteristics indistinguishable from those of CGCL and is caused by mutations mostly present in exon 9 of the SH3BP2 gene. In this study, we investigated four cases of CGCL and one case of cherubism. DNA was extracted from peripheral blood and tumor tissue and all coding and flanking regions of the SH3BP2 amplified by PCR and directly sequenced to identify underlying mutations. Two novel mutations were found; a heterozygous missense mutation c.1442A>T (Q481L) in exon 11 in one sporadic case of CGCL and a heterozygous germline and tumor tissue missense mutation c.320C>T (T107M) in exon 4 in one patient with cherubism. These findings open a new window to investigate the possible relationship between the pathogenesis of the cherubism and CGCL.

tagenized chicken smooth muscle myosin light chain cDNAs were digested with BamHI and EcoRI, the products were purified by low-melting-point agarose gel electrophoresis, and the concentration was estimated by comparison against known standards. For the amplification ofthe vasopressin V2 receptor, 100 ng of genomic DNA, isolated from peripheral blood by digestion with SDS/proteinase K followed by phenol/chloroform extraction and isopropanol precipitation (6), was subjected to 35 cycles of specific PCR. The annealing temperature used was 640C for 1 min, and the denaturation and extension temperatures were, respectively, 94CC and 720C. The primers used were NDI-1 (5'-TCTGCAGATGGT-

Craniopharyngiomas and pituitary adenomas are both tumors of the hypothalamic and pituitary region, respectively that are frequently associated with endocrine defects either because of direct involvement of hormone producing cells (most pituitary tumors) or because of secondary defects due to disturbance of hypothalamic function (some pituitary tumors and craniopharyngiomas). Some studies suggest that mutant beta-catenin gene cells in craniopharyngiomas and pituitary adenomas contribute to their tumorigenesis. DNA was extracted from 73 cranial tumors and subjected to polymerase chain reaction (PCR) with previously described primers encompassing glycogen synthase kinase-3beta phosphorylation sites of the beta-catenin gene. Sequenced PCR products for possible beta-catenin gene mutations showed a total of 7/43 alterations in adamantinomatous craniopharyngioma-derived DNA samples. Two previously described beta-catenin mutations in codon 33 TCT(Ser) > TGT(Cys) and codon 37 TCT(Ser) > TTT(Phe), whereas three novel mutations in codon 41 ACC(Thr) > ATC(Ile), codon 33 TCT(Ser) > TAT(Tyr) and codon 32 GAC(Asp) > AAC(Asn) were observed. None of the 22 pituitary adenomas and the eight papillary craniopharyngiomas analyzed presented any sequence alterations. These findings demonstrate an association between beta-catenin gene alterations and craniopharyngiomas of the adamantinomatous type. Since this gene product is involved with development, these results suggest that beta-catenin mutations may contribute to the initiation and subsequent growth of congenital craniopharyngiomas.

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