Genetic Disorder Solved Through Genome Sequencing?

DNA Error
In a recent medical breakthrough, researchers from The University of Queensland’s Institute for Molecular Bioscience (IMB) have successfully used whole genome sequencing to identify a new genetic disorder and solve the mystery afflicting a three-year-old child.

According to the child’s parents, he experienced developmental problems and leg spasticity when he was 12 months. Initially, doctors assumed the condition to be leukodystrophy, which is caused by progressive degeneration of the white matter in the brain and the spinal cord. This affects the motor control, and children may exhibit abnormal muscle stiffness.  Generally, this condition is known to be caused by mutations in the EIF2B1, EIF2B2, EIF2B3, EIF2B4, and EIF2B5 genes.

However, the team, led by Dr Ryan Taft had found, through genomics, that a mutation in the DARS gene had been the underlying cause. This new disorder – which causes Hypomyelination in the brain stem and spinal cord leading to leg spasticity – has been named HBSL.

Dr Taft and his team, in their previous research, used gene sequencing to identify the genetic mutation causing the leukodystrophy, H-ABC. Both the findings were published in the American Journal of Human Genetics.

A single alteration in a gene can, potentially, change the functioning of the particular gene, which may lead to a diseased condition. According to the World Health Organization, approximately 10,000 genetic disorders are caused by an error in a gene in the human DNA, known as pure genetic diseases.

Researchers have considered diagnosing the cause of the disorder to be the most important step towards developing an efficient treatment strategy. The experts consider genetic research, along with other clinical specialties, to be the future of medicine and health care.

Genetic research solved through genome sequencing has paved the way for improvised treatment strategies by the development of personalized medicine. This methodology helps identify a patient’s response to a particular drug and prevent any adverse side effects.

Many genetic disorders are still being identified, as their occurrences are uncommon and the symptoms may easily be confused with other disorders, often leading to misdiagnosis. In the US, there are nearly 7000 rare diseases.

Very recently, researchers used gene sequencing for selecting embryos for invitro fertilization. This technology, which is said to revolutionize the screening process for IVF was reported at the annual meeting of ESHRE by Dr Dagan Wells of the NIHR Biomedical Research Centre at the University of Oxford, UK.

It was observed that only 30% of the embryos actually get implanted while transferring the selected embryos. Genetic mutations and chromosomal defects are being blamed for this high rate of failure.

In order to increase the implantation success rate, Dr Wells and his team developed a new Next Generation Sequencing (NGS) technique to screen the embryos for possible genetic defects. This method has been found to reveal chromosomal abnormalities, which are held responsible for miscarriages. Moreover, the method is said to be cost-effective and provide very fast analysis reports; within 16 hours.

Researchers had successfully identified a good embryo and implanted it into women undergoing IVF treatment. Both the implantations resulted in healthy pregnancies, with one giving birth to a fine boy last month. This is a huge step forward and could have a significant impact on IVF treatments. Researchers have planned to conduct a randomized clinical trial to prove the efficacy of the technique.This research, that has solved genetic disorders through genome sequencing, could potentially identify unknown diseases and optimize treatments to suit every individual’s need.

The 3rd annual US Conference on Rare Diseases & Orphan Products 2013-The New Era in Health Care is scheduled this year from October 7 to October 9 and will be held at the Bethesda Marriott North.

Written by: Janet Grace Ortigas

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