Discovery opens way to genetic disorders treatment

SCIENTISTS have pinpointed a gene linked to birth defects which could open the way to treatments for a range of disorders.

The international group of researchers including experts from Yorkshire identified the genetic cause of an inherited condition that causes severe foetal abnormalities.

The work by geneticists from Leeds University and institutions 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 through genetic screening.

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But their findings, which show how the disease gene stops cells' finger-like antennae, known as cilia, from detecting and relaying information, may ultimately lead to treatments for more common related disorders, such as spina bifida and polycystic kidney disease.

Leeds researcher Prof Colin Johnson said: "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.

"Spina bifida, for example, is one of the most common birth defects, affecting in one in every 1,000 children."

Meckel-Gruber syndrome and Joubert syndrome are part of a wider family of disorders known as 'ciliopathies' – so-called because the cilia are not working as they should and do not respond properly to signals.

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.

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 laboratory.

The work identified a previously unknown gene – TMEM216 – as a cause of the syndromes.

Because Meckel-Gruber and Joubert syndromes are recessive disorders, only couples who both have a copy of the disease gene are at risk of conceiving babies with these birth defects.