Sunday, January 10, 2010

IVF babies ‘risk major diseases’

Another chicken and egg finding. IVF babies have SLIGHTLY higher incidence of problems but is that due to the method of their conception or prior defects in their parents? The latter seems by far the most probable

Scientists have discovered that the DNA of babies conceived through IVF differs from that of other children, putting them at greater risk of diseases such as diabetes and obesity later in life. The new research could explain why IVF babies tend to be at higher risk of low birth weight, defects and rare metabolic disorders.

The changes are not in the genes themselves but in the mechanism that switches them on and off, the study of which is known as epigenetics. “These epigenetic differences have the potential to affect embyronic development and foetal growth, as well as influencing long-term patterns of gene expression associated with increased risk of many human diseases,” said Professor Carmen Sapienza, a geneticist at Temple University in Philadelphia, who jointly led the research. There is a possibility that such changes could be transmitted to the children of IVF babies, meaning they could spread through the human gene pool.

In their findings, published in the Human Molecular Genetics journal, Sapienza and his colleagues took blood samples from the placenta and umbilical cords of 10 IVF children and 13 children who were naturally conceived. They studied the DNA of cells taken from the blood to see if there were differences in the level of methylation. This is the process by which molecules known as methyl groups are attached to genes to shut them down when they are not needed.

The results showed that the level of methylation in the cells taken from IVF babies was significantly lower — implying that some genes were becoming active at the wrong times. “We have shown that in vitro conception is associated with differences in gene methylation and that some of these differences may affect gene expression,” said Sapienza.

The findings could have serious implications for the booming industry in assisted reproduction. About 40,000 women a year undergo IVF in Britain, often paying tens of thousands of pounds in the hope of conceiving. Some 15,000 IVF babies are born each year — about 2% of all births — so they are a significant component of the UK gene pool.

Sapienza, however, was unable to ascertain the actual cause of the epigenetic changes he observed. One possibility is that couples who are infertile may have naturally higher levels of epigenetic changes than the rest of the population, perhaps explaining the cause of their infertility.


Brain scan could diagnose autism early

This is highly dubious. Mental speed is also related to IQ

Children could be screened for autism at an early age after scientists developed a way to recognise the condition using brain scans. Diagnosis of autism has always been difficult and often the condition is recognised at too late a stage for treatment to have a major effect.

But now researchers believe they have discovered a potential way of spotting the disorder in early infancy by scanning the brainwaves. They have discovered that children with autism spectrum disorders (ASD) recognise sound a fraction of a second slower (11 milliseconds) than unaffected children. This is significant because it can be picked up by a brain scan and so become a standardised way to diagnose the condition.

Dr Timothy Roberts, the lead researcher at Children's Hospital in Philadelphia, said the scan could become the first "standard tool" for recognising autism. His tests showed that the delay is present in children with autism aged 10 and if further tests prove the same is true in much younger children then it could lead to widespread screening. "An 11-millisecond delay is brief, but it means, for instance, that a child with ASD, on hearing the word ‘elephant’ is still processing the ‘el’ sound while other children have moved on," he said. "The delays may cascade as a conversation progresses, and the child may lag behind typically developing peers.”

It is estimated that around one in 100 children between five-years-old and nine-years-old have autism, meaning there are around 500,000 in Britain. The condition covers a wide spectrum of disorders with cases ranging from relatively mild problems with social interaction to more severe difficulties in behaviour such as not speaking, copying, rigid routines and social isolation.

While the causes of the condition remain a mystery, early and intensive treatment is known to help alleviate the symptoms. The problem is that diagnosis can be difficult and often relies on waiting for the symptoms to develop by which time a lot of damage has been done.

In the current study, published in the journal Autism Research, Dr Roberts used a magnetoencephalography (MEG), a scanner that detects magnetic fields in the brain. Using a helmet that surrounds the child’s head, the team presents a series of recorded beeps, vowels and sentences. As the child’s brain responds to each sound, non-invasive detectors in the MEG machine analyse the brain’s changing magnetic fields.

The researchers compared 25 children with ASDs with an average age of 10 years to 17 age-matched typically developing children. The children with ASDs had an average delay of 11 milliseconds (about 1/100 of a second) in their brain responses to sounds, compared to the control children. Among the group with ASDs, the delays were similar, whether or not the children had language impairments.

The system may be able to diagnose ASDs as early as infancy, permitting possible earlier intervention with treatments. They also may be able to differentiate types of ASDs such as classic autism and Asperger’s syndrome in individual patients.

Autistic children who are taught intensively at home at the age of three can double their IQ within two years, it is believed. Dr. Gina Gómez de la Cuesta, Action Research Leader at the National Autistic Society, said: “The initial findings of this small scale study are useful. “Many children still have to wait years for a diagnosis and so without the right support this can have a profound effect on them and their families. "Early diagnosis and intervention can make a huge difference to peoples' lives if the right environment, education and services can be put in place as soon as possible."


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