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Biomedical subjects

J Goldblatt

Publications and source records attributed to J Goldblatt.

At least 55 records · Page 3Linked to original sources

Variable penetrance of familial pheochromocytoma associated with the von Hipple Lindau gene mutation, S68W. Mutations in brief no. 150. Online.

Van Hippel-Lindau disease (VHL) is an autosomal dominantly inherited disorder, characterised by the development of clear cell renal carcinomas, CNS hemangioblastomas, retinal angiomas, pancreatic tumors, pheochromocytomas and hepatic cysts. Recently a number of families with dominant familial pheochromocytoma as the only clinical manifestation have been reported to carry mutations in the HVL gene. We describe a family in which a novel VHL S68W mutation was segregating and carrier individuals manifested with variable penetrance of isolated pheochromocytomas. Investigation of this kindred confirmed that a mutation in the VHL gene could produce isolated pheochromocytomas as the only clinical feature and was variably penetrant.

Genes, Tumor Suppressor↗

Association of polymorphisms within the tumour necrosis factor (TNF) genes and childhood asthma.

BACKGROUND: Tumour necrosis factor alpha (TNFalpha) is a potent modulator of immune and inflammatory responses, and has been implicated in a variety of autoimmune diseases, including asthma. Increased levels of TNFalpha have been detected in both sputa and bronchoalveolar lavage fluid of asthmatic subjects during acute attacks. Interindividual variation in TNFalpha levels may be genetically determined and polymorphisms within the TNF genes and nearby HLA Class II region have been associated with differences in TNFalpha production. OBJECTIVE: To investigate the association of differences in asthma-related phenotypes with two biallelic polymorphisms: a G to A substitution at position - 308 of the TNFalpha gene promoter (TNF1 and TNF2 alleles) and an NcoI polymorphism in the first intron of the lymphotoxin alpha gene (LT-alpha*1 and LT-alpha*2 alleles). METHODS: The regions of interest were amplified from genomic DNA using specific primers and PCR. Dot blot analysis was used for genotyping individuals for the TNFalpha - 308 polymorphism, while restriction enzyme digestion was used for genotyping individuals for the LT-alpha gene NcoI polymorphism. A case-control analysis was then performed on 74 asthmatic and 50 non-asthmatic unrelated children for each polymorphism. RESULTS: The TNFalpha - 308 TNF1 allele was present at a significantly higher frequency in cases than controls (OR= 2.4, P=0.003), and homozygosity for the TNF1 allele was associated with a fivefold increased risk of physician diagnosed asthma relative to the other genotypes (OR = 5.23, P = 0.004). The LT-alpha*2 allele showed similar associations, including an approximately fivefold higher risk of physician diagnosed asthma for LT-alpha*2 homozygotes (OR = 4.89, P = 0.019). Evidence of a significant linear trend in asthma risk across the three genotypes was found for both polymorphisms. CONCLUSION: These results suggest an important role for the TNFalpha gene or a linked locus in an inherited asthma diathesis.

Alleles↗

Semen levels of mitochondrial DNA deletions in men attending an infertility clinic do not correlate with phenotype.

In view of previous reports associating mitochondrial DNA deletions with male reproductive disorders, levels of the 'common' 4977 bp mitochondrial DNA deletion were evaluated semi-quantitatively in 64 men, without prior knowledge of the clinical diagnosis. Significant levels of deletions were detected in 34/64 men (53%) but 29 of these (45%) had a normal semen profile and were phenotypically normal. No deletions were detected in 30 men, of whom 21 were normospermic, six were oligozoospermic and three were azoospermic. It is concluded that although mitochondrial DNA deletions within the testis may be associated with primary testicular disease, no correlation with semen quality was evident in this study, thus limiting its potential use as a diagnostic test.

DNA, Mitochondrial↗

A polymorphism of the CC16 gene is associated with an increased risk of asthma.

Several quantitative traits associated with the asthma phenotype have been linked to markers on chromosome 11q13, although the gene responsible has yet to be well established. The gene for Clara cell secretory protein (CC16) is an ideal candidate for involvement in an inherited predisposition to asthma because of its chromosomal location, the role of the CC16 protein in controlling airway inflammation, and differences in levels of the protein between asthmatics and healthy controls. All three CC16 exons were screened in an unselected population of 266 subjects from 76 families and a cohort of 52 severely asthmatic children. A combination of single strand conformational polymorphism (SSCP) analysis, heteroduplex analysis, DNA sequencing, and restriction digestion was used. Mutation detection methods identified an adenine to guanine substitution in the CC16 gene at position 38 (A38G) downstream from the transcription initiation site within the non-coding region of exon 1. In the unselected population, 43.6% were homozygous for the polymorphic sequence (38GG) and 46.2% were heterozygous (38AG). All the asthmatic and unaffected children from both populations were selected for an unmatched case control analysis consisting of 67 asthmatic and 46 unaffected subjects. Those homozygous for the published sequence (38AA) had a 6.9-fold increased risk of developing asthma (p=0.049) and heterozygotes (38AG) a 4.2-fold increased risk (p=0.028). Modelling of genotype as a continuous covariate indicated evidence of a significant linear trend across the three genotypes (odds ratio=2.84 per unit increase in genotype code, p=0.018). These associations were independent of age, gender, and tobacco smoke exposure. These data and the known anti-inflammatory role of CC16 in the respiratory tract suggest that alteration to the gene at position 38 may contribute to asthma.

Asthma↗

Linkage of chromosome 5q and 11q gene markers to asthma-associated quantitative traits in Australian children.

Asthma is a genetically complex disease, and the investigation of putative linkages to candidate loci in independent populations is an important part of the gene discovery process. This study investigated the linkage of microsatellite markers in the 5q and 11q regions to asthma-associated quantitative traits in 121 Australian Caucasian nuclear families. The families were recruited on the basis of a child proband: a cohort of 95 randomly recruited families of unselected probands (n = 442 subjects) and a cohort of 26 families of probands selected on the basis of severe symptomatic asthma (n = 134 subjects). The quantitative traits assessed included serum levels of total IgE and specific IgE to house dust mite and mixed grass, blood eosinophil counts, and the dose-response slope (DRS) of FEV1 to histamine provocation. Multipoint linkage analysis using Haseman-Elston sib-pair methods provided evidence of significant linkage between the chromosome 5q markers and loge total serum IgE levels, specific serum IgE levels, and loge blood eosinophil counts. The chromosome 11q markers showed evidence of significant linkage to specific serum IgE levels. Neither region demonstrated significant linkage to the loge DRS to histamine. Phenotypes were residualized for age and sex. These data are consistent with the existence of loci regulating asthma-associated quantitative traits in both the 5q31-33 and 11q13 chromosomal regions.

Adolescent↗

Multicenter evaluation of the Bayer Immuno I CA 15-3 assay.

We conducted a multicenter evaluation of the analytical and clinical features of the automated Bayer Immuno 1 CA 15-3 assay and compared assay performance to two manual tests. Results of the 10-day imprecision study of the Bayer Immuno 1 assay pooled across four evaluation sites and three lots of reagent produced total CV < or = 4%. Lot-to-lot reproducibility for 26 different lots of reagents and calibrators manufactured over a 2-year period was demonstrated (CV, 1.1%). Results for the Bayer Immuno 1 assay correlated well with the Biomira TRUQUANT BR 27.29 and Centocor CA 15-3 RIAs (r > or = 0.94). The upper limit of the reference interval for the Bayer Immuno 1 assay was 35.9 kilounits/L (35.9 units/mL); values were similar for all methods. Longitudinal monitoring of healthy women yielded assay values with an average CV of 11% and 21% for the Bayer Immuno 1 and Biomira assays, respectively. The Bayer Immuno 1 assay demonstrated the analytical features, intermethod correlation, and long-term performance characteristics that are essential for longitudinal monitoring of breast cancer patients.

Adolescent↗

Mutation screening of interferon-gamma (IFNgamma) as a candidate gene for asthma.

BACKGROUND: Reduced levels of interferon gamma (IFNgamma) mRNA and protein have been detected in the bronchoalveolar lavage fluid of atopic asthmatics. IFNgamma is secreted by TH1 cells while IL-4 and IL-5 are secreted by TH2 cells and an imbalance in the TH1/TH2 response may be responsible for atopic asthma. The gene for IFNgamma is located on chromosome 12; a region of the genome which has been shown in linkage studies to be associated with asthma. OBJECTIVE: To determine if there are any mutations present in the coding exons and 5' flanking region of the IFNgamma gene in atopic asthmatic subjects compared with controls to explain the lower levels of this cytokine as an inherited, rather than acquired, factor in the asthmatic subjects. METHODS: The four exons and 5' flanking region of the IFNgamma gene were amplified by polymerase chain reaction (PCR) from genomic DNA of 265 individuals from a Western Australian and a Venezuelan population. The PCR products were examined by single strand conformational polymorphism and heteroduplex analyses to see if there were any changes in the DNA migration patterns which would suggest the presence of a sequence variation. RESULTS: The four exons and the 5' flanking region of the IFNgamma gene were amplified from 265 individuals from two populations. Single strand conformational polymorphism and heteroduplex analyses did not reveal any mutations in the regions examined. CONCLUSION: The gene for IFNgamma appears to be highly conserved as no sequence variations were detected in 265 individuals. These results suggest that mutations of the IFNgamma gene are unlikely to be a significant cause of an inherited asthma diathesis.

Adolescent↗

A syndrome of leukonychia totalis and multiple sebaceous cysts.

We report on a family with leukonychia totalis, koilonychia and multiple sebaceous cysts segregating as an autosomal dominant disorder. This condition has only previously been described in two kindreds, and this report documents the natural course of the disorder and provides further evidence for pancreatitis being an associated syndromic feature.

Adult↗

Dentofacial features of a family with Crouzon syndrome. Case reports.

Crouzon syndrome is an autosomal dominant condition characterized by craniosynostosis with associated dentofacial anomalies. This paper describes the variable clinical features in affected individuals over two generations of a family with particular reference to the dentofacial deformities and discussion of management strategies.

Adolescent↗

Evaluation of a project to enhance knowledge of hereditary diseases and management.

During 1992 and 1993, in a designated suburban area of Perth, Western Australia, information on hereditary disease was provided for health professionals and the general community. This information was in the form of posters, pamphlets, postal flyers and return letter cards, a static display, newspaper articles, advertisements and radio broadcasts, and professional seminars. The aim of this project was to evaluate the effectiveness of combined strategies to convey practical information about hereditary disease to the community and health professionals. Multiple measures of response evaluation were used, which included structured questionnaire surveys of health professionals and members of the community before and after the project. In the community surveys, respondents who were female, married, middle aged, and parents, and had a higher level of education or were born in Australia, New Zealand, or the United Kingdom were generally better informed about hereditary diseases. This intervention resulted in only meagre changes in community knowledge about hereditary disease, even though promotional materials were shown to be appropriate. General Practitioners (GPs) and Child Health Nurses (CHNs) were supportive of clinical genetic services and recognised a need for continuation of education in this field. There is a rapidly increasing need for community and health professional comprehension of the applications of the new genetic technology. This project indicates that routine educational and health promotion strategies will not be enough to achieve desired levels of knowledge and attitude change.

Adult↗

Further evidence for preaxial hallucal polydactyly as a marker of diabetic embryopathy.

Maternal diabetes has an established aetiological link with developmental abnormalities, and the prevalence of major congenital malformations in the offspring of affected women is approximately 4-8%, compared to the general population risk of about 3%. Hallucal polydactyly, particularly with an unusual proximal placement of the extra digit, has been reported as a distinctive anomaly in diabetic embryopathy. We report on a child of a diabetic mother with this unusual form of hallucal polydactyly, together with other skeletal anomalies, confirming that this malformation is a useful clinical marker for the diagnosis of diabetic embryopathy.

Abnormalities, Multiple↗

Further evidence for a syndrome of "apple peel" intestinal atresia, ocular anomalies and microcephaly.

We report on a male child with "apple peel" atresia, associated with microcephaly, with subsequent hydrocephalus, short stature, moderate global developmental delay and ocular abnormalities. A similar phenotype was previously reported by Stromme et al. in 1993 in female siblings, and this description of another affected individual provides further evidence for this being a distinct syndromic entity.

Abnormalities, Multiple↗

The impact of antenatal screening for Down syndrome in Western Australia: 1980-1994.

Since the early 1970s, women in Western Australia have been screened for fetal Down syndrome risk on the basis of maternal age. Women 35 years of age or more at delivery, were offered fetal karyotyping with genetic diagnostic testing via amniocentesis or chorionic villus sampling. An increase in the prevalence of Down syndrome of 3.9% per year (95% confidence interval: 1.8-6.0%) was observed between 1980 and 1994, almost all of which was accounted for by increased maternal age. In 1991, a maternal serum screening (MSS) programme for Down syndrome was first implemented in Western Australia and has since evolved in 6 separate laboratories providing Down risk assessment in 1994. The gradual introduction of MSS programmes had little discernible impact until 1994, when 38% of Down syndrome fetuses were ascertained as a result of increased-risk MSS tests and the birth prevalence of Down syndrome decreased significantly. In this report, we review antenatal screening programmes and their impact on the birth prevalence of Down syndrome in Western Australia.

Adult↗