Defective gene linked to foetal abnormalities

London, May 31 (IANS) Researchers have identified the genetic defect that causes severe foetal abnormalities.

The work, co-led by geneticists at the University of Leeds and colleagues in Paris, Rome and San Diego, should allow couples at risk of conceiving babies with the profoundly disabling Meckel-Gruber and Joubert syndromes to be identified beforehand.

These two syndromes are part of a wider family of disorders known as ‘ciliopathies’ – so-called because the cilia, cell’s finger-like antennae, are not working as they should and do not respond properly to signals.

These findings may ultimately lead to treatments for more common related disorders, such as spina bifida and polycystic kidney disease.

‘By understanding the science behind this relatively rare condition, we can gain insight into other developmental conditions that are less serious but far more frequent,’ said University of Leeds researcher Colin A. Johnson, professor.

‘Spina bifida, for example, is one of the most common birth defects, affecting one in every 1,000 children,’ said Johnson, who led the study.

This lack of communication can prevent the neural tube from developing correctly in growing embryos, leading to abnormalities in the brain.

‘Affected embryos can also develop abnormalities in the eyes, extra fingers or toes, and multiple cysts in their kidneys. These defects are often only picked up on a 12 week ultrasound scan,’ said Johnson.

To find the gene responsible for Meckel-Gruber and Joubert syndromes, the researchers examined DNA from families with a history of the disorder, from skin cells donated by patients, and from cells grown in the lab.

The work identified a previously unknown gene – TMEM216 – as a cause of Meckel-Gruber and Joubert syndromes, said a Leeds release.

They also showed that the faulty TMEM216 gene stopped cells from making a protein that is needed for signalling.

The paper has been published in Nature Genetics.