FW: Abstracts: 2 on Autism, 1 Nutrition, 1 Crohn's

[Guest guest]

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Subject: Autism: evidence of association with adenosine deaminase genetic

polymorphism.

Neurogenetics 2001 Mar;3(2):111-3

Autism: evidence of association with adenosine deaminase genetic

polymorphism.

Bottini N, De Luca D, Saccucci P, Fiumara A, Elia M, Porfirio MC, Lucarelli

P, Curatolo P.

Department of Internal Medicine, Tor Vergata University of Rome, Rome,

Italy.

Reduced adenosine deaminase (ADA) activity has been reported in sera of

autistic children relative to controls. Additionally, the Asn allele of the

ADA Asp8Asn polymorphism has been associated with reduced enzymatic

activity.

Therefore, we studied this polymorphism in autistic children and controls

from two Italian populations. We observed a significantly elevated frequency

of the low-activity Asn allele in the total sample of autistic cases

relative

to controls (P < 0.00001), and in both study populations (P < 0.001 and P <

0.025). We suggest that this putative genotype-dependent reduction in ADA

activity may be a risk factor for the development of autism.

PMID: 11354825 [PubMed - in process]

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Subject: Evidence for a Susceptibility Gene for Autism on Chromosome 2 and

for Genetic He

Am J Hum Genet 2001 Jun;68(6):1514-1520

Evidence for a Susceptibility Gene for Autism on Chromosome 2 and for

Genetic

Heterogeneity.

Buxbaum JD, Silverman JM, CJ, Kilifarski M, Reichert J, Hollander E,

Lawlor BA, Fitzgerald M, Greenberg DA, KL.

Laboratory of Molecular Neuropsychiatry, Departments of Psychiatry and

Neurobiology, and Seaver Autism Research Center, Mount Sinai School of

Medicine, New York, NY, 10029, USA. buxbaj01@...

Although there is considerable evidence for a strong genetic component to

idiopathic autism, several genomewide screens for susceptibility genes have

been performed with limited concordance of linked loci, reflecting either

numerous genes of weak effect and/or sample heterogeneity. Because

decreasing

sample heterogeneity would increase the power to identify genes, the effect

on evidence for linkage of restricting a sample of autism-affected relative

pairs to those with delayed onset (at age >36 mo) of phrase speech (PSD, for

phrase speech delay) was studied. In the second stage of a two-stage genome

screen for susceptibility loci involving 95 families with two or more

individuals with autism or related disorders, a maximal multipoint

heterogeneity LOD score (HLOD) of 1.96 and a maximal multipoint

nonparametric

linkage (NPL) score of 2.39 was seen on chromosome 2q. Restricting the

analysis to the subset of families (n=49) with two or more individuals

having

a narrow diagnosis of autism and PSD generated a maximal multipoint HLOD

score of 2.99 and an NPL score of 3.32. The increased scores in the

restricted sample, together with evidence for heterogeneity in the entire

sample, indicate that the restricted sample comprises a population that is

more genetically homogeneous, which could therefore increase the likelihood

of positional cloning of susceptibility loci.

PMID: 11353400 [PubMed - as supplied by publisher]

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Subject: Genetic aspects of nutrition and toxicology: report of a workshop.

J Am Coll Nutr 2001 Apr;20(2 Suppl):119-28

Genetic aspects of nutrition and toxicology: report of a workshop.

Archer MC, son TW, Strain JJ.

Deportment of Nutritional Sciences, University of Toronto, Ontario, Canada.

m.archer@...

The health and resilience of humans and animals is, in large part,

determined

by the quality and quantity of the diet. This, in turn, may influence an

individual's capability to deal with stress including toxic insult. In

addition, there may be specific components of the diet that modulate the

toxicity of specific toxicants whether the latter are ingested as food or

absorbed via other routes. Many examples attest to the importance of

interactions between dietary components and toxicants after absorption in

the

body. Such interactions occur at every level of biological organization from

the molecular to the whole organism. Some may be synergistic, others

antagonistic. Some may involve direct chemical reaction between the nutrient

molecule and the toxicant, others may occur by indirect action at the

cellular or organ levels. All examples point to the importance of

considering

diet when measuring the response to toxic agents whether in animals or

humans. In order to foster interaction between the sciences of nutrition and

toxicology, The Heinz Institute of Nutritional Sciences as sponsoring a

series of workshops. The first of these was held in June, 1999 at the

University of Ulster to address evolutionary aspects of

nutrition--toxicology

(for report see Eur. J. Nutr, 39, 49-52, 2000). In June, 2000, a second

workshop was held at the University of Toronto to address genetic aspects,

and this is a brief summary of the proceedings. We are beginning to

understand the molecular basis of the regulation of gene expression by

dietary factors and how genetic changes can affect response to toxicants.

Recent advances in technology and a detailed understanding of disease

etiology has led to the ability to study molecular determinants of disease

risk. The workshop provided a forum for nutritionists, toxicologists,

molecular biologists, epidemiologists and others to discuss common interests

and to merge their efforts towards an integrated approach to

nutrition--toxicology via genetics and genomics. The first session dealt

with

the mechanism by which nutrients such as fatty acids (e), amino acids

(Jefferson) and metal ions (Cousins) can regulate gene expression. In the

second session, there were presentations on the effects of nutritional

factors on genes of toxicological significance such as phase I and phase II

enzymes of drug metabolism (Guengerich, Goodfellow and Grant) as well as on

oxidative DNA damage and its repair (, Weindruch). Session three

dealt

with gene-nutrient interactions in the development of chronic diseases such

as diabetes (Hegele, Berdanier) and cancer (Kim, Ambrosone et al.). New

developments such as DNA microarrays (McGlynn) and the use of transgenic and

knockout models (Sehayek) were presented in the final session.

PMID: 11349934 [PubMed - in process]

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Subject: Scientists identify gene defect for Crohn's disease

Scientists identify gene defect for Crohn's disease

LONDON, May 21 (Reuters) - Scientists on both sides of the Atlantic said on

Monday they have independently identified a gene linked to Crohn's disease,

a

digestive disorder that attacks mainly young adults.

In two papers published in the science journal Nature, American and European

teams of researchers describe how a mutation in a gene called Nod2 can

increase a person's susceptibility to the illness.

The discovery, which will be presented by both groups at a medical

conference

in Atlanta, Georgia, sheds new light on the complex relationship between

genes and the environment and could spearhead new treatments.

" Finding this crucial genetic clue gives us our first clear insight into the

complex causes and mechanism of Crohn's disease, " said Judy Cho, of the

University of Chicago, who co-authored one of the research studies.

The illness strikes about one in every 1,000 people in western countries.

Many sufferers are under the age of 30. The cause of the chronic

inflammatory

illness is unknown but scientists suspect is it due to genetic as well as

environmental factors.

There is no cure but treatments can suppress the symptoms such as abdominal

pain, diarrhoea, fever and weight loss.

Nunez, of the University of Michigan and a member of the American

team, said scientists had suspected there was a link between the genes and

bacteria residing in the gut that leads to the development of the disease.

" The discovery of Nod2 may explain this missing-link connection between

genes

and bacteria, " he said in a statement.

Dr Gilles , of the Dausset Foundation in Paris, and a team of

European scientists said Nod2 is not the only gene involved in Crohn's

disease but its discovery may help researchers find the others.

" It will also contribute to the identification of associated environmental

factors and focus the search for specific therapies, " he said in the Nature

report.

The researchers suspect Nod2 and another gene called Nod1 are involved in

how

the body's immune system reacts to bacteria in the gut.

Having one copy of the abnormal gene doubles the risk of developing the

illness. Two mutated genes increase the chances 15 to 20 fold.

About 15 percent of patients with Crohn's disease have the the mutated gene,

according to the scientists.

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