Genetics and autism

[Guest guest]

Hi,

I pulled this from another forum - not sure I am completely in

agreement with it though. If autism is not genetic how come it

appears/seems to run in families. As for not all family members

having it - that just stands to reason - maybe one twin got a better

set of genes than the other.

I'm not sure if it should concern me the amount of research and money

going into this either? If the research is used for good reasons all

well and good - but could this kind of research lead to aborting

those suspected to have autism? I do not believe it is the

information itself that is at fault, but how that said information is

then used.

Also I like to keep an open mind on such things and do not believe

scientists know everything - although they attempt to - and neither

are they always correct.

Autism Behaviour Types Are Not Genetically Linked

(2005-09-04)

Scientists at the MRC (Medical Research Council, UK) Social, Genetic

and Developmental Psychiatry Centre at the Institute of Psychiatry,

King's College London, have discovered that two sets of behaviours

that co-occur in autism spectrum conditions appear to be caused by

different sets of genes.

The report by Dr in collaboration with Professor

Plomin and Dr Francesca Happé - published in Developmental

Science - could help advance future diagnosis, treatment and

understanding of autism spectrum conditions.

In an autism diagnosis, two types of behaviours must be displayed;

those that reflect social impairment such as a difficulty in making

friends and non-social obsessive and repetitive behaviours such as

sticking to rigid routines. These two types of symptoms can both have

massive impact on children's development. The researchers were

motivated to investigate these two components separately because they

represent two very different types of behaviours and it is not clear

why they co-occur in autism spectrum conditions.

The study collected data from the UK-based Twins Early Development

Study (TEDS) through parent and teacher reports on 3000 pairs of

seven-year-old twins. Participants completed a questionnaire designed

to assess social and non-social behaviours that are characteristic of

autism spectrum conditions but also seen in the general population.

The questions assessed the extent to which the twins displayed a

range of behaviours, such as how considerate of other people's

feelings they are or whether they are fussy and over-particular.

The researchers found that identical twins (where each twin shares

the same set of genes) tended to show similar levels of social

impairments to each other: i.e. both twins would show either many or

few social impairments. In contrast, fraternal twins (where only a

proportion of their genes are shared) often had very different levels

of social impairments to each other. The same pattern of results was

found in the twins for non-social behaviours. This demonstrated that

both social and non-social behaviours are highly heritable, that is,

a large proportion of the variation of these types of behaviours in

the general population is due to genetic influences.

The researchers then posed themselves a new question: whether social

and non-social behaviours are influenced by the same set of genes. If

the same genes operate on both, one would expect high correlations

between social impairments in one twin and non-social behaviours in

the other twin in identical twin pairs. Lower correlations would be

expected in fraternal twins because they do not share all their genes.

The researchers did not find evidence to suggest that the same genes

are involved. They found that social and non-social impairments did

not correlate very highly and in many cases, for example, if one

identical twin showed social impairments, their co-twin did not show

any non-social impairments. The results of this study indicated that

most of the genes influencing social impairments are different to

those that influence non-social behaviours.

Dr said: " This study suggests for the first time that

social and non-social behaviours, which are both shown in autism

spectrum conditions, are caused by mainly different sets of genes. It

suggests that 'genes for autism' is a misnomer: there are several

genetically distinct components involved. This finding has important

implications for DNA and brain studies: it may be better to study the

social and non-social components separately rather than requiring

that a child has both components, which is what traditional diagnosis

requires. "

The Medical Research Council (MRC) is a national organisation funded

by the UK tax-payer. Its business is medical research aimed at

improving human health; everyone stands to benefit from the outputs.

The research it supports and the scientists it trains meet the needs

of the health services, the pharmaceutical and other health-related

industries and the academic world. MRC has funded work which has led

to some of the most significant discoveries and achievements in

medicine in the UK. About half of the MRC's expenditure of more than

£500 million is invested in its 40 Institutes, Units and Centres.

The

remaining half goes in the form of grant support and training awards

to individuals and teams in universities and medical schools. Web

site at: http://www.mrc.ac.uk.

King's College London (http://www.kcl.ac.uk) is one of the two oldest

and largest colleges of the University of London with over 13,800

undergraduate students and nearly 5,700 postgraduates in nine schools

of study. It is a member of the Group: a coalition of the

UK's major research-based universities. The College has had 24 of its

subject-areas awarded the highest rating of 5* and 5 for research

quality, demonstrating excellence at an international level, and it

has recently received an excellent result in its audit by the Quality

Assurance Agency. King's is in the top group of UK universities for

research earnings, with income from grants and contracts of £100

million, and has an annual turnover of more than £348 million. In

2004 the College was once again awarded an AA- financial credit

rating from Standard & Poor's.

The Institute of Psychiatry (http://www.iop.kcl.ac.uk) is a world-

renowned centre for treatment, research and training in psychiatry

and mental health. Part of King's College London, it is closely

affiliated to the South London and Maudsley NHS Trust and King's

College Hospital NHS Trust. The organisation is involved in

pioneering new and improved ways of understanding and treating mental

illness and brain disease. Its wide-ranging field of work includes

depression, eating disorders, brain imaging, genetics and psychosis.

The Institute was one of only two organisations in the field of

psychiatry which received a five star rating in the 2001 Research

Assessment Exercise conducted by the Higher Education Funding Council

for England.

Courtesy of Newswire