Search PubMed⌕ Search

Biomedical subjects

Martin Bobrow

Publications and source records attributed to Martin Bobrow.

9 recordsLinked to original sources
PubMed2006

Mutations in the gene encoding the Sigma 2 subunit of the adaptor protein 1 complex, AP1S2, cause X-linked mental retardation.

In a systematic sequencing screen of the coding exons of the X chromosome in 250 families with X-linked mental retardation (XLMR), we identified two nonsense mutations and one consensus splice-site mutation in the AP1S2 gene on Xp22 in three families. Affected individuals in these families showed mild-to-profound mental retardation. Other features included hypotonia early in life and delay in walking. AP1S2 encodes an adaptin protein that constitutes part of the adaptor protein complex found at the cytoplasmic face of coated vesicles located at the Golgi complex. The complex mediates the recruitment of clathrin to the vesicle membrane. Aberrant endocytic processing through disruption of adaptor protein complexes is likely to result from the AP1S2 mutations identified in the three XLMR-affected families, and such defects may plausibly cause abnormal synaptic development and function. AP1S2 is the first reported XLMR gene that encodes a protein directly involved in the assembly of endocytic vesicles.

Adaptor Protein Complex sigma Subunits↗
PubMed2004

Psychological impact of genetic testing for familial hypercholesterolemia within a previously aware population: a randomized controlled trial.

This trial tests the hypothesis that confirming a clinical diagnosis of familial hypercholesterolemia (FH) by finding a genetic mutation reduces patients' perceptions of control over the disease and adherence to risk-reducing behaviors. Three hundred forty-one families, comprising 341 hypercholesterolemia probands and 128 adult relatives, were randomized to one of two groups: (a) routine clinical diagnosis; (b) routine clinical diagnosis plus genetic testing (mutation searching in probands and direct gene testing in relatives). The main outcome measures were perceptions of control over hypercholesterolemia, adherence to cholesterol-lowering medication, diet, physical activity, and smoking. There was no support for the main hypothesis: finding a mutation had no impact on perceived control or adherence to risk-reducing behavior (all P-values > 0.10). While all groups believed that lowering cholesterol was an effective way of reducing the risk of a heart attack, participants in whom a mutation was found believed less strongly in the efficacy of diet in reducing their cholesterol level (P = 0.02 at 6 months) and showed a trend in believing more strongly in the efficacy of cholesterol-lowering medication (P = 0.06 at 6 months). In conclusion, finding a mutation to confirm a clinical diagnosis of FH in a previously aware population does not reduce perceptions of control or adherence to risk-reducing behaviors. The pattern of findings leads to the new hypothesis that genetic testing does not affect the extent to which people feel they have control over a condition, but does affect their perceptions of how control is most effectively achieved. Further work is needed to determine whether similar results will be obtained in populations with little previous awareness of their risks.

Adult↗
PubMed2004

Mutations in the DLG3 gene cause nonsyndromic X-linked mental retardation.

We have identified truncating mutations in the human DLG3 (neuroendocrine dlg) gene in 4 of 329 families with moderate to severe X-linked mental retardation. DLG3 encodes synapse-associated protein 102 (SAP102), a member of the membrane-associated guanylate kinase protein family. Neuronal SAP102 is expressed during early brain development and is localized to the postsynaptic density of excitatory synapses. It is composed of three amino-terminal PDZ domains, an src homology domain, and a carboxyl-terminal guanylate kinase domain. The PDZ domains interact directly with the NR2 subunits of the NMDA glutamate receptor and with other proteins responsible for NMDA receptor localization, immobilization, and signaling. The mutations identified in this study all introduce premature stop codons within or before the third PDZ domain, and it is likely that this impairs the ability of SAP102 to interact with the NMDA receptor and/or other proteins involved in downstream NMDA receptor signaling pathways. NMDA receptors have been implicated in the induction of certain forms of synaptic plasticity, such as long-term potentiation and long-term depression, and these changes in synaptic efficacy have been proposed as neural mechanisms underlying memory and learning. The disruption of NMDA receptor targeting or signaling, as a result of the loss of SAP102, may lead to altered synaptic plasticity and may explain the intellectual impairment observed in individuals with DLG3 mutations.

Base Sequence↗
PubMed2003

Genetic information and testing in insurance and employment: technical, social and ethical issues.

The present paper examines the professional and scientific views on the social, ethical and legal issues that impact on genetic information and testing in insurance and employment in Europe. For this purpose, many aspects have been considered, such as the concerns of medical geneticists, of the insurers and employers, of the public, as well as the regulatory frameworks and unresolved issues. The method used was primarily the review of the technical, social, economical and ethical aspects of advances in genetics and the concerns of parties who are involved, that is, the insurers, the employers and the public. The existing guidelines and legislation on this topic were also reported. Then, the method was to examine the issues debated by these parties in Europe, as well as by 47 experts from 14 European countries invited to an international workshop organized by the European Society of Human Genetics Public and Professional Policy Committee in Manchester, UK, 25-27 February 2000. The result of this was that the most important issues raised by genetic information and testing in insurance and employment in Europe include a need for clear definitions of terms used in genetics, declaring the grounds on which genetic information is or is not used, and promoting confidence between the public and the insurance industry. There is currently very little use of genetic information in relation to employment, but the situation should be kept under review.

Employment↗
PubMed2002

Polygenic susceptibility to breast cancer and implications for prevention.

The knowledge of human genetic variation that will come from the human genome sequence makes feasible a polygenic approach to disease prevention, in which it will be possible to identify individuals as susceptible by their genotype profile and to prevent disease by targeting interventions to those at risk. There is doubt, however, regarding the magnitude of these genetic effects and thus the potential to apply them to either individuals or populations. We have therefore examined the potential for prediction of risk based on common genetic variation using data from a population-based series of individuals with breast cancer. The data are compatible with a log-normal distribution of genetic risk in the population that is sufficiently wide to provide useful discrimination of high- and low-risk groups. Assuming all of the susceptibility genes could be identified, the half of the population at highest risk would account for 88% of all affected individuals. By contrast, if currently identified risk factors for breast cancer were used to stratify the population, the half of the population at highest risk would account for only 62% of all cases. These results suggest that the construction and use of genetic-risk profiles may provide significant improvements in the efficacy of population-based programs of intervention for cancers and other diseases.

Breast Neoplasms↗
PubMed2002

Outcomes of pregnancies diagnosed with Klinefelter syndrome: the possible influence of health professionals.

OBJECTIVE: To describe the association between the outcomes of pregnancies diagnosed with Klinefelter syndrome (KS) and the specialty of the health professional providing pre- and post-diagnostic counselling. METHOD: Data were extracted from the case notes of the 111 cases of KS diagnosed prenatally between 1986 and 1997 in eight geographical regions in five European countries. The data extracted included: outcome of pregnancy, maternal age, social class, parity, gestational age at diagnosis, year of diagnosis and specialties of the health professionals conducting pre- and post-diagnosis consultations. RESULTS: The overall termination rate was 44% (49/111: 95% confidence interval: 35 to 54). Using multivariable logistic regression analysis, the only significant predictor of continuation of the pregnancy was the specialties of the health professionals conducting post-diagnosis counselling: the affected pregnancy was more likely to continue when post-diagnosis counselling involved only a genetics specialist (relative risk: 2.42 (1.14 to 5.92)). CONCLUSION: There is an association between whether or not a woman terminates a pregnancy affected by an unfamiliar fetal anomaly and the professional background of the health professional providing post-diagnostic counselling. The causal nature of this association remains to be determined.

Abortion, Eugenic↗
PubMed2002

Patenting DNA.

The protection of inventions based on human DNA sequences has been achieved mainly through application of the patent system. Over the past decade, there has been continuing debate about whether this use of intellectual property rights is acceptable. Companies and universities have been active during this period in filing thousands of patent applications. Although many have argued that to claim a DNA sequence in a patent is to claim a discovery, patent law allows discoveries that are useful to be claimed as part of an invention. As the technology to isolate DNA sequences has advanced, the criterion for inventiveness, necessary for any invention to be eligible for filing, has become more difficult to justify in the case of claims to DNA sequences. Moreover, the discovery that a gene is associated with a particular disease is, it is argued, to discover a fact about the world and undeserving of the status of an invention. Careful examination of the grounds for allowing the patenting of DNA sequences as research tools suggests such rewards will rarely be justified. The patenting of DNA sequences as chemical intermediates necessary for the manufacture of therapeutic proteins is, however, reasonable given that the information within the sequence is applied to produce a tangible substance which has application as a medicine. Despite the legal, technical and political complexities of applying the flexibilities with the current law, it is argued that much could be achieved in the area of patenting DNA by raising the thresholds for patentability.

Animals↗
PubMedDate not supplied

Panel discussion.

Explore the source record for details and available documents.

Adolescent↗