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J Wirth

Publications and source records attributed to J Wirth.

At least 19 recordsLinked to original sources
PubMed2001

Clinical and molecular-cytogenetic studies in seven patients with ring chromosome 18.

We report the results of detailed clinical and molecular-cytogenetic studies in seven patients with ring chromosome 18. Classical cytogenetics and fluorescence in situ hybridization (FISH) analysis with the chromosome 18 painting probe identified five non-mosaic and two complex mosaic 46,XX,dup(18)(p11.2)/47,XX,dup(18)(p11.2),+r(18) and 46,XX,dup(18)(p11.32)/47,XX,dup(18)(p11.32),+r(18) cases. FISH analysis was performed for precise characterization of the chromosome 18 breakpoints using chromosome 18-specific short-arm paint, centromeric, subtelomeric, and a panel of fifteen Alu- and DOP-PCR YAC probes. The breakpoints were assessed with an average resolution of approximately 2.2 Mb. In all r(18) chromosomes, the 18q terminal deletions ranging from 18q21.2 to 18q22.3 ( approximately 35 and 9 Mb, respectively) were found, whereas only in four cases could the loss of 18p material be demonstrated. In two cases the dup(18) chromosomes were identified as inv dup(18)(qter-->p11.32::q21.3-->qter) and inv dup(18)(qter-->p11.32::p11.32-->p11.1: :q21.3-->qter)pat, with no evidence of an 18p deletion. A novel inter-intrachromatid mechanism of formation of duplications and ring chromosomes is proposed. Although the effect of "ring instability syndrome" cannot be excluded, the phenotypes of our patients with characteristic features of 18q- and 18p- syndromes are compared and correlated with the analyzed genotypes. It has been observed that a short neck with absence of cardiac anomalies may be related to the deletion of the 18p material from the r(18) chromosome.

Abnormalities, Multiple↗
PubMed2001

Functional hemizygosity of PAFAH1B3 due to a PAFAH1B3-CLK2 fusion gene in a female with mental retardation, ataxia and atrophy of the brain.

We report on the molecular characterization of a translocation t(1;19)(q21.3;q13.2) in a female with mental retardation, ataxia and atrophy of the brain. Sequence analysis of the breakpoints revealed an ALU:-repeat-mediated mechanism of recombination that led to truncation of two genes: the kinase CLK2 and PAFAH1B3, the gene product of which interacts with LIS1 as part of a heterotrimeric G protein complex PAF-AH1B. In addition, two reciprocal fusion genes are present. One expressed fusion gene encodes the first 136 amino acids of PAFAH1B3 followed by the complete CLK2 protein. Truncated PAFAH1B3 protein lost its potential to interact with LIS1 whereas CLK2 activity was conserved within the fusion protein. These data emphasize the importance of PAF-AH1B in brain development and functioning and demonstrate the first fusion gene apparently not associated with cancer.

Abnormalities, Multiple↗
PubMed2001

Girl with phenotypic abnormalities and a de novo, apparently balanced translocation 46,XX,t(5;10)(q35.2q11.2).

We describe a three-year-old girl with a triangular face, epicanthus, midfacial hypoplasia, apparently low-set ears, a small mouth with thin vermilion border, and a small chin, hypermobile joints, developmental delay with insecure gait, dystonic movement disorder, speech defect, and a history of unexplained undernutrition. She has a de novo, apparently balanced translocation t(5;10)(q35.2;q11.2). Using fluorescence in situ hybridization (FISH), we located the breakpoints in the 1.5-Mb area defined by YAC 753f5 (5q35.2) and within the approximately 2-Mb interval between 10cen and YAC 933a3 (10q11.21).

Child, Preschool↗
PubMed2001

A translocation breakpoint cluster disrupts the newly defined 3' end of the SNURF-SNRPN transcription unit on chromosome 15.

Balanced translocations affecting the paternal copy of 15q11--q13 are a rare cause of Prader-Willi syndrome (PWS) or PWS-like features. Here we report on the cytogenetic and molecular characterization of a de novo balanced reciprocal translocation t(X;15)(q28;q12) in a female patient with atypical PWS. The translocation breakpoints in this patient and two previously reported patients map 70-80 kb distal to the SNURF-SNRPN gene and define a breakpoint cluster region. The breakpoints disrupt one of several hitherto unknown 3' exons of this gene. Using RT--PCR we demonstrate that sequences distal to the breakpoint, including the recently identified C/D box small nucleolar RNA (snoRNA) gene cluster HBII-85 as well as IPW and PAR1, are not expressed in the patient. Our data suggest that lack of expression of these sequences contributes to the PWS phenotype.

Adult↗
PubMed2001

Volatile compounds released by enzymatic hydrolysis of glycoconjugates of leaves and grape berries from Vitis vinifera Muscat of Alexandria and Shiraz cultivars.

Glycoconjugates from Muscat of Alexandria and Shiraz leaves and grape berries were isolated by adsorption on Amberlite XAD-2 resin, and enzymatically released aglycons were analyzed by GC-FID and GC-MS. About 120 aglycons were fully or tentatively identified. Compositional differences were observed between leaves and berries of the two varieties in five aglycon chemical groups: C6 alcohols, aliphatic alcohols, monoterpenes, shikimates, and C(13)-norisoprenoids, which were much more abundant in the leaves than in the berries. The differences observed for C(13)-norisoprenoids were in agreement with their hypothetical independent biosynthesis in leaves and berries. Thus, 3-hydroxy-beta-damascone, an important norisoprenoid aglycon of grape berries, was not detected in leaves, whereas its oxidized derivative, 3-oxo-alpha-damascone, was absent in berries. Compositional differences were also observed between Muscat and Shiraz leaves. 3-Oxo-alpha-ionol was not detected in Shiraz leaves, and its retro derivatives were less abundant than in Muscat of Alexandria leaves. Conversely, in Shiraz leaves the levels of 7,8-dihydroionone derivatives, such as megastigman-3,9-diol and 3-oxo-7,8-dihydro-alpha-ionol, were higher than in Muscat of Alexandria leaves.

Fruit↗
PubMed2001

Influence of gender on rates of hospitalization, hospital course, and hypercapnea in high-risk patients admitted for asthma : a 10-year retrospective study at Yale-New Haven Hospital.

STUDY OBJECTIVES: To compare the relative numbers and hospital course of men vs women admitted at least twice with asthma or status asthmaticus to Yale-New Haven Hospital (YNHH) during the period from 1985 to 1994. DESIGN: A retrospective chart review. SETTING: YNHH. PATIENTS: High-risk men and women (age range, 18 to 50 years) admitted at least twice during the study period with the discharge diagnosis of asthma or status asthmaticus. RESULTS: Of 561 adult asthma patients admitted during the study period, 188 were admitted at least twice and accounted for 68% of the total asthma admissions. One hundred three of the 188 patients were randomly selected, and all of their asthma admissions were retrospectively reviewed. The 103 patients accounted for 382 admissions. Seventy-two percent of these patients and 68.6% of the admissions were women. The proportions of each gender requiring admission to the medical ICU (15.65% women vs 11.67% men) or intubation (8.00% women vs 5.80% men) were not significantly different. Women did exhibit a definite trend toward longer admissions (4.92 days vs 4.04 days; p < 0.554). A significantly higher proportion of female patient admissions underwent initial arterial blood gas analysis than men (56.9% vs 44.2%; p < 0.05). Factorial analysis demonstrated a highly significant main effect of gender on PCO(2) levels (p < 0.0001). Men, overall, had higher PCO(2) levels than women (48.73 mm Hg vs 41.04 mm Hg; p < 0.036). Male patients admitted to the medical ICU or requiring intubation had significantly higher PCO(2) levels than their respective female counterparts (p < 0.05). CONCLUSIONS: At YNHH, 68% of all admissions for asthma in this age group are attributable to high-risk patients. High-risk female patients are admitted twice as often as high-risk male patients and tend to have longer admissions. Once admitted, however, the proportion of men and women requiring the medical MICU or intubation were similar. High-risk male patients on presentation are consistently more hypercapneic than high-risk female patients. Therefore, the mechanisms contributing to the gender differences in asthma admissions may include differences in the ventilatory response to hypercapnea or in the tolerance to airway obstruction.

Adolescent↗
PubMed2000

Molecular cloning of the critical region for glomerulopathy with fibronectin deposits (GFND) and evaluation of candidate genes.

Glomerulopathy with fibronectin deposits (GFND, MIM 601894) is an autosomal dominant kidney disease that leads to terminal renal failure at a median age of 47 years. It represents a distinct entity of membranoproliferative glomerulonephritis (MPGN) type III and is characterized by the unique feature of massive glomerular deposits of fibronectin. We have recently localized a gene locus for GFND to human chromosome 1q32 by total genome linkage analysis in a large kindred, within a 4.1-cM critical interval between markers D1S2872 and D1S2891. This interval contains a cluster of genes for "regulators of complement activation" (RCA), which represent strong candidates for GFND. To identify positional candidate genes for GFND within the critical genetic interval, we here report the cloning of the entire critical GFND region in a complete YAC and partial PAC contig. We constructed a high-resolution transcriptional map, thereby defining positional and functional candidate genes for the disease. To evaluate their role in GFND, we performed functional studies on RCA proteins in GFND patients from the large kindred, as well as mutational analysis of the genes for complement receptor-2 (CR2), membrane cofactor protein (MCP), and decay accelerating factor (DAF). Although no loss-of-function mutation has been identified as yet, these data provide a basis for the examination of candidate genes for GFND and other genes for MPGN, which localize to the vicinity of the GFND region.

Adult↗
PubMed2000

DXS6673E encodes a predominantly nuclear protein, and its mouse ortholog DXHXS6673E is alternatively spliced in a developmental- and tissue-specific manner.

DXS6673E is a candidate gene for nonspecific X-linked mental retardation and encodes a novel Zn-finger protein. The ortholog murine gene DXHXS6673E in XC-D was isolated and characterized. It is ubiquitously expressed in all embryonic stages and adult tissues. Two different transcription start sites exist that result in two major transcripts of 6055 and 5352 nucleotides, each composed of 25 exons. Exon 1A is tissue specific, whereas exon 1B is transcribed constitutively. Both variants are translated into the same 1370-amino-acid protein. Transcripts are subject to alternative splicing at the 5'-end. Some of the isoforms are developmental stage and tissue specific. Among them, one was present only in embryos and adult brain. Sequence analysis demonstrated evolutionary conservation down to the arthropods and defined several conserved protein motifs. Subcellular localization studies with green fluorescent protein as a reporter showed that DXS6673E is predominantly located in the nucleus due to several functional nuclear localization signals. Three distinct protein distribution patterns in COS-7 cells could be identified.

Alternative Splicing↗
PubMed2000

High resolution comparative genomic hybridisation analysis reveals imbalances in dyschromosomal patients with normal or apparently balanced conventional karyotypes.

A sensitive technique is needed for screening whole genome imbalances in dyschromosomal patients when G-banding shows normal karyotypes or apparently balanced translocations. In this study we performed highly sensitive comparative genomic hybridisation analysis on a number of such cases and revealed chromosomal imbalances in all.

Chromosome Aberrations↗
PubMed2000

Improved accuracy in the diagnosis of intrahepatic bile duct ectasia in Caroli's disease by combination of ultrasound and endoscopic retrograde cholangiography.

Caroli's disease is characterized by dilatation of the intrahepatic bile ducts. Cholangitis, liver cirrhosis and development of a cholangiocarcinoma are possible complications. For optimal therapy, a correct diagnosis of the extent of the disease is mandatory. The present report demonstrates that the combination of endoscopic retrograde cholangiography and ultrasound may lead to a more reliable diagnosis of the extent of Caroli's disease. It is therefore essential to perform ultrasound in all these patients.

Bile Duct Diseases↗
PubMed2000

Molecular cytogenetic characterisation of partial trisomy 9q in a case with pyloric stenosis and a review.

Partial trisomy 9q represents a rare and heterogeneous group of chromosomal aberrations characterised by various clinical features including pyloric stenosis. Here, we describe the case of a 1 year old female patient with different dysmorphic features including pyloric stenosis and prenatally detected partial trisomy 9q. This partial trisomy 9q has been analysed in detail to determine the size of the duplication and to characterise the chromosomal breakpoints. According to the data gained by different molecular cytogenetic techniques, such as fluorescence in situ hybridisation (FISH) with whole and partial chromosome painting probes, yeast artificial chromosome (YAC) probes, and comparative genomic hybridisation (CGH), the derivative chromosome 9 can be described as dup(9)(pter-->q22. 1::q31.1-->q22.1::q31.1--> q22.1::q31.1-->qter). Four breakpoint spanning YACs have been identified (y806f02, y906g6, y945f5, and y747b3) for the proximal breakpoint. According to this new case and previously published data, the recently postulated putative critical region for pyloric stenosis can be narrowed down to the subbands 9q22.1-q31.1 and is the result of either partial trisomy of gene(s) located in this region or a gene disrupted in 9q31.

Chromosome Banding↗
PubMed2000

Molecular cloning of Xp11 breakpoints in two unrelated mentally retarded females with X;autosome translocations.

Mental retardation is a very common and extremely heterogeneous disorder that affects about 3% of the human population. Its molecular basis is largely unknown, but many loci have been mapped to the X chromosome. We report on two mentally retarded females with X;autosome translocations and breakpoints in Xp11, viz., t(X;17)(p11;p13) and t(X;20)(p11;q13). (Fiber-) FISH analysis assigned the breakpoints to different subbands, Xp11.4 and Xp11.23, separated by approximately 8 Mb. High-resolution mapping of the X- chromosome breakpoints using Southern blot hybridization resulted in the isolation of breakpoint-spanning genomic subclones of 3 kb and 0. 5 kb. The Xp11.4 breakpoint is contained within a single copy sequence, whereas the Xp11.23 breakpoint sequence resembles an L1 repetitive element. Several expressed sequences map close to the breakpoints, but none was found to be inactivated. Therefore, mechanisms other than disruption of X-chromosome genes likely cause the phenotypes.

Adolescent↗
PubMed1999

Mouse Dac, a novel nuclear factor with homology to Drosophila dachshund shows a dynamic expression in the neural crest, the eye, the neocortex, and the limb bud.

Dac is a novel nuclear factor in mouse and humans that shares homology with Drosophila dachshund (dac). Alignment with available sequences defines a conserved box of 117 amino acids that shares weak homology with the proto-oncogene Ski and Sno. Dac expression is found in various neuroectodermal and mesenchymal tissues. At early developmental stages Dac is expressed in lateral mesoderm and in neural crest cells. In the neural plate/tube Dac expression is initially seen in the prosencephalon and gets gradually restricted to the presumptive neocortex and the distal portion of the outgrowing optic vesicle. Furthermore, Dac transcripts are detected in the mesenchyme underlying the Apical Ectodermal Ridge (AER) of the extending limb bud, the dorsal root ganglia and chain ganglia, and the mesenchyme of the growing genitalia. Dac expression in the Gli 3 mutant extra toes (Xt/Xt) shows little difference compared to the expression in wild-type limb buds. In contrast, a significant expansion of Dac expression are observed in the anterior mesenchyme of the limb buds of hemimelic extra toes (Hx/+) mice. FISH analysis reveals that human DAC maps to chromosome 13q22.3-23 and further fine-mapping defined a position of the DAC gene at 54cM or 13q21.1, a locus that associates with mental retardation and skeletal abnormalities.

Amino Acid Sequence↗
PubMed1999

Molecular cytogenetic detection of 9q34 breakpoints associated with nail patella syndrome.

The nail patella syndrome (NPS1) is an autosomal dominant disorder characterised by dysplasia of the finger nails and skeletal abnormalities. NPS1 has been mapped to 9q34, to a 1 cM interval between D9S315 and the adenylate kinase gene (AK1). We have mapped the breakpoints within the candidate NPS1 region in two unrelated patients with balanced translocations. One patient [46,XY,t(1;9)(q32.1;q34)] was detected during a systematic survey of old cytogenetic files in Denmark and southern Sweden. The other patient [46,XY,t(9;17)(q34.1;q25)] was reported previously. D9S315 and AK1 were used to isolate YACs, from which endclones were used to isolate PACs. Two overlapping PAC clones span the 9q34 breakpoints in both patients, suggesting that NPS1 is caused by haploinsufficiency due to truncation or otherwise inactivation of a gene at or in the vicinity of the breakpoints.

Chromosome Fragility↗
PubMed1999

The anemia in continuous ambulatory peritoneal dialysis patients is related to Kt/V index.

Anemia in chronic renal failure causes a number of serious problems to the patient. As a result, it is imperative to make use of all rational options to alleviate it. The present study addresses the question, the answer to which is not yet known, whether or not the degree of anemia depends on the efficacy of continuous ambulatory peritoneal dialysis (CAPD) and, if so, what the importance of peritoneal clearance and residual renal function is. A significant correlation between the hematocrit (Hct) and the total weekly Kt/V index (tKt/V) (r = 0.61, p<0.01), total weekly creatinine clearance (tCLCR) (r = 0.50, p<0.05), and residual glomerular filtration rate (r = 0.43, p<0.05) was demonstrated in a group of 22 CAPD patients. Stepwise regression analysis showed that of all the variables monitored, Hct depends exclusively on tKt/V (p<0.01, r2 = 0.37). The value of Hct in a group of patients with a tKt/V <2.3 (n = 15) was 28.9+/-1.2% (arithmetic mean +/- SEM) while in a group with a tKt/V > or =2.3 (n = 7), it was 35.1+/-1.9% (p<0.01). On dividing tKt/V and tCLCR into their peritoneal and renal components, a significant correlation between Hct and renal Kt/V (r = 0.47, p<0.05) was found; stepwise regression analysis identified renal Kt/V (p<0.01) and peritoneal Kt/V (p<0.05), with R2 = 0.38 as major variables with an effect on Hct. The authors conclude the efficacy of blood purification is another factor affecting renal anemia in CAPD patients. The relationship between anemia and blood purification is best expressed using the Kt/V index. The Kt/V provided by one's own kidneys seems to be of greater importance for anemia than the Kt/V provided by peritoneal dialysis. The results provide the basis for prospective interventional studies.

Adult↗
PubMed1999

Systematic characterisation of disease associated balanced chromosome rearrangements by FISH: cytogenetically and genetically anchored YACs identify microdeletions and candidate regions for mental retardation genes.

Disease associated balanced chromosome rearrangements (DBCRs) have been instrumental in the isolation of many disease genes. To facilitate the molecular cytogenetic characterisation of DBCRs, we have generated a set of >1200 non-chimeric, cytogenetically and genetically anchored CEPH YACs, on average one per 3 cM, spaced over the entire human genome. By fluorescence in situ hybridisation (FISH), we have performed a systematic search for YACs spanning translocation breakpoints. Patients with DBCRs and either syndromic or non-syndromic mental retardation (MR) were ascertained through the Mendelian Cytogenetics Network (MCN), a collaborative effort of, at present, 270 cytogenetic laboratories throughout the world. In this pilot study, we have characterised 10 different MR associated chromosome regions delineating candidate regions for MR. Five of these regions are narrowed to breakpoint spanning YACs, three of which are located on chromosomes 13q21, 13q22, and 13q32, respectively, one on chromosome 4p14, and one on 6q25. In two out of six DBCRs, we found cytogenetically cryptic deletions of 3-5 Mb on one or both translocation chromosomes. Thus, cryptic deletions may be an important cause of disease in seemingly balanced chromosome rearrangements that are associated with a disease phenotype. Our region specific FISH probes, which are available to MCN members, can be a powerful tool in clinical cytogenetics and positional cloning.

Adolescent↗