We have previously identified megdkaryocyte stimulating factor (MSF) gene expression by synovial fibroblasts as the origin of lubricin in the synovial cavity. Lubricin is a mucinous glycoprotein responsible for the boundary lubrication of articular cartilage. MSF has a significant homology to vitronectin and is composed of 12 exons. RNA was purified from human synovial fibroblasts and articular chondrocytes grown in vitro from tissue explants obtained from subjects without degenerative joint disease. RT-PCR was used with multiple complimentary primer pairs spanning the central mucin expressing exon 6 of the MSF gene and individual exons on both the N-and C-terminal sides of exon 6. Exons 2, 4 and 5 appear to be variably expressed by synovial fibroblasts and articular chondrocytes. Lubricating mucin, in the form of MSF, is expressed by both chondrocytes and synovial fibroblasts in vitro.Both lubricin and superficial zone protein (SZP), a related proteoglycan, share a similar primary structure but could differ in posttranslational modifications with 0-linked oligosaccharides which are predominant in lubricin and with limited amounts chondroitin and keratan sulfate found in SZP. Since most of the MSF exons are involved in the expression of lubricating mucin. a strong homology to vitronectin persists. It is therefore appropriate to consider that both SZP and lubricin occupy a new class of biomolecules termed tvihonectins. Screening of a human genome bacterial artificial chromsoine (BAC) library with a cDN A primer pair complimentary for exon 6 identified two clones. Both clones were complimentary for chromosome lq25 by in situ hybridization. This same locus was previously implicated in camptodactyl-arthropathy-pericarditis syndrome (CAP) by genetic mapping. It is hypothesized that CAP, a large joint arthropathy, may be associated with ineffective boundary lubrication provided by synovial fluid. 0

Objective Recently, Christianson syndrome (CS) has been determined to be caused by mutations in the X-linked Na+/H+ Exchanger 6 (NHE6). We aimed to determine the diagnostic criteria and mutational spectrum for CS. Methods Twelve independent pedigrees (14 boys, ages 4 to 19) with mutations in NHE6 were administered standardized research assessments and mutations were characterized. Results The mutational spectrum was composed of 9 single nucleotide variants (SNVs), 2 indels and 1 CNV deletion. All mutations were protein-truncating or splicing mutations. We identified two recurrent mutations (c.1498 c>t, p.R500X; and c.1710 g>a, p.W570X). Otherwise, all mutations were unique. In our study, seven of 12 mutations (58%) were de novo, in contrast to prior literature wherein mutations were largely inherited. We also report prominent neurological, medical and behavioral symptoms. All CS participants were non-verbal and had intellectual disability, epilepsy and ataxia. Many had prior diagnoses of autism and/or Angelman syndrome. Other neurologic symptoms included eye movement abnormalities (79%), postnatal microcephaly (92%) and MRI evidence of cerebellar atrophy (33%). Regression was noted in 50%, with recurrent presentations involving loss of words and/or the ability to walk. Medical symptoms, particularly gastrointestinal symptoms, were common. Height and body mass index measures were below normal ranges in most participants. Behavioral symptoms included hyperkinetic behavior (100%) and a majority exhibited high pain threshold. Interpretation This is the largest cohort of independent CS pedigrees reported. We propose diagnostic criteria for CS. CS represents a novel neurogenetic disorder with general relevance to autism, intellectual disability, Angelman syndrome, epilepsy and regression.

To characterize the differences between second trimester Down syndrome (DS) and euploid fetuses, we used Affymetrix microarrays to compare gene expression in uncultured amniotic fluid supernatant samples. Functional pathway analysis highlighted the importance of oxidative stress, ion transport, and G protein signaling in the DS fetuses. Further evidence supporting these results was derived by correlating the observed gene expression patterns to those of small molecule drugs via the Connectivity Map. Our results suggest that there are secondary adverse consequences of DS evident in the second trimester, leading to testable hypotheses about possible antenatal therapy for DS.antenatal therapy ͉ Connectivity Map ͉ gene expression ͉ prenatal diagnosis ͉ trisomy 21

Novel systemic treatments are needed in pancreatic cancer. The authors sought to establish the frequency of overexpression of the HER-2/neu oncogene in patients with pancreatic adenocarcinoma to determine the potential role of trastuzumab (Herceptin) as a therapeutic agent in this disease. Tumor specimens from patients with pancreatic adenocarcinoma were analyzed by staining for p185HER2 protein using the DAKO immunohistochemical assay. Patients with and without HER-2/neu overexpression by immunohistochemistry were compared with respect to clinical and pathologic characteristics. HER-2/neu gene amplification was also evaluated by fluorescence in situ hybridization (FISH). Thirty-two of 154 patients (21%) had pancreatic adenocarcinoma that demonstrated HER-2/neu overexpression by immunohistochemistry. At initial diagnosis, 16% of resectable cancers, 17% of locally advanced cancers, and 26% of metastatic cancers were determined to have HER-2/neu overexpression. Three of 11 (27%) patients with HER-2/neu overexpression by immunohistochemistry had gene amplification by FISH. HER-2/neu overexpression occurs in a subset of pancreatic cancer. Evaluation of the efficacy of trastuzumab for patients with pancreatic cancer who overexpress HER-2/neu appears indicated.

Human chromosome 21 has been analyzed by pulsed‐field gel electrophoresis using somatic cell hybrids containing limited regions of the chromosome and greater than 60 unique sequence probes. Thirty‐three independent NotI fragments have been identified, totalling 43 million bp. This must account for essentially the entire long arm, and therefore gaps remaining in the map must be small. The extent of the pulsed‐field map has allowed the direct correlation of the physical map with the cytogenetic map: translocation breakpoints can be unambiguously positioned along the long arm and the distances between them measured in base pairs. Three breakpoints have been identified, providing physical confirmation of cytogenetic landmarks. Information on sequence organization has been obtained: (i) 60% of the unique sequence probes are located within 11 physical linkage groups which can be contained in only 20% of the long arm; (ii) 9/21 genes are clustered within 4%; (iii) translocation breakpoints appear to occur within CpG island regions, making their identification difficult by pulsed‐field techniques. This analysis contributes to the human genome mapping effort, and provides information to guide the rapid investigation of the biology of chromosome 21.

The response rate of Herceptin and gemcitabine is similar to gemcitabine alone. The 7-month median survival in patients with metastatic pancreatic cancer suggests there may be a modest benefit for some patients. Infrequent HER-2/neu overexpression limits the role of targeting the HER-2/neu gene and prevents definitive conclusions on the addition of Herceptin to gemcibine for patients with pancreatic cancer.

ECAUSE OF THE INHERENT DIF-ficulties with research on human fetuses, the analysis of fetal gene expression has in large part been limited to the examination of tissue from human abortuses and the assessment of animal models for genes and developmental pathways that are conserved across species. Fetal monitoring in vivo is limited to noninvasive methods such as the measurement of uterine size or anatomic evaluation by fetal sonography. In addition, genetic analysis can be performed on amniotic fluid components, including amniocytes, which typically require time-consuming expansion in vitro before use, and cellfree proteins in the amniotic fluid, such as ␣-fetoprotein, which can serve as biomarkers for genetic anomalies. The cellfree component of the amniotic fluid is discarded after these analyses and is therefore available for research and future clinical applications.Cell-free fetal DNA in the serum and plasma of pregnant women was first described by Lo et al 1 in 1997 after others demonstrated the presence of circulating tumor-specific DNA sequences in cancer patients. [2][3][4] After it was shown that cell-free fetal DNA is also present in the urine of pregnant women, 5 we hypothesized that amniotic fluid, as a reservoir of fetal urine, would contain fetal DNA. In a preliminary study, we demonstrated that much larger quantities of fetal DNA are present in amniotic fluid than in maternal serum (100-to 200-fold difference). 6

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