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Sperm linked to ART-related genetic disorders

7 December 2009
Appeared in BioNews 537

Mutations in sperm used for IVF and ICSI may be responsible for causing the rare genetic disorders potentially associated with these techniques.

Disorders like Beckwith-Wiedemann syndrome have increased among children born by assisted reproductive technologies (ART). Assisted conception techniques, such as in vitro culturing, have been blamed. A study published in the European Journal of Human Genetics has shown that, in some cases, the cause may be errors in the father's sperm associated with infertility.

Beckwith-Wiedemann syndrome is caused by errors in genetic imprinting- the activation or deactivation of genes during development dependent on which parent they come from. A process called DNA methylation is critical to imprinting. A team led by Dr Takahiro Arima from Tohoku University examined DNA methylation in 78 six to nine-week-old embryos and fetuses conceived using ART, and 38 conceived without ART. They also examined the father's sperm and DNA. In seven of 17 cases where there was abnormal DNA methylation in the ART sample, identical alterations were present in the father's sperm. The abnormal DNA methylation in the sperm was associated with variations in a gene coding for DNMT3L - a key enzyme in DNA methylation associated with abnormal imprinting and low sperm count.

In their paper, the team recommends that routine sperm screening during assisted conception should include imprint methylation analysis and that this could 'substantially reduce the likelihood of abnormal samples being used in ART'.

Using the analysis techniques, the team examined the methylation status of seven Autosoma imprinted genes (H19, GTL2, PEG1, KCNQ10T1, ZAC, PEG3 and SNRPN) and the XIST gene, which is linked to the X-chromosome. The methylation status of non-imprinted sequences of repeating DNA called Alu and LINE1 was also examined, and the team found no detectable differences between the ART and normal samples.


Inheritance of abnormal imprints in ART
European Journal of Human Genetics |  27 May 2009
19 July 2010 - by Dr Marianne Kennedy 
A gene crucial for sperm production in humans is also needed to make sperm in many other animals including mice, sea urchins, flies and worms, scientists in Chicago, US, have discovered...
1 March 2010 - by Dr Sophie Pryor 
Women who undergo fertility treatment are four times more likely to have a stillborn baby than those who conceive naturally or use other methods, according to a new study...
1 March 2010 - by Maren Urner 
An IVF technique whereby fertilisation is achieved by injecting an individual sperm into an egg cell is being overused and may pass on infertility to the next generation, the scientist who developed the technique has warned...
18 January 2010 - by Professor Marcus Pembrey 
Readers will have noticed a couple of news reports and Rosalind John's excellent commentary on this topic in the last few weeks, but I make no apology for returning to the subject so soon. I believe this area of research will spark interest from the media for years to come. This is not because I fear research will necessarily uncover some unsuspected risk to the health of people born after IVF (we can't know until we do the research) but because we are ...
11 December 2009 - by Dr Rosalind M John 
The aim of assisted reproductive technology (ART) is to achieve a single most important goal, the birth of a healthy child. ART is responsible for the birth of over 200,000 children each year worldwide. In the most common form of infertility treatment - IVF - the woman's eggs are collected and then combined with the man's sperm in a petri dish. The successfully fertilised eggs are then transferred into the woman's womb. In ...
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