Genetic defect responsible for epilepsy and mental retardation foundOctober 13th, 2010 - 5:29 pm ICT by ANI
Washington, Oct 13 (ANI): Researchers have detected a genetic mutation responsible for severe mental retardation and epilepsy beginning at infancy.
The team, led by Ohad Birk of the Ben-Gurion University, determined that the defect is associated with the production of the 21st amino acid, selenocysteine (SEC), which leads to progressive brain atrophy.
Birk said: “One out of every 40 Jews of both Moroccan and Iraqi ancestry may be carriers of this mutation. As the disease is both severe and common, testing for these mutations is expected to become a routine prenatal genetic screening test in these two populations, enabling prevention of future cases.”
As the disease is progressive, elucidation of its molecular mechanisms might open new venues to treatment, preventing disease progression.
The human genetic code, as deciphered some 50 years ago, encodes 20 amino acids, which are the building blocks of all proteins in the human body.
However, in recent years it became apparent that a 21st amino acid exists: selenium, entering the body in food, is incorporated in the human tissues into what is known as selenocysteine.
This 21st amino acid is unique in that it is encoded by what is normally a stop codon - that is, a DNA sequence that normally instructs the protein building system to end the chain of amino acids, terminating the generated protein.
In contrast with most genes, some 25 genes have a unique component that manipulates the stop codon so that instead of terminating the evolving protein chain, it inserts at that point an SEC building block.
The study was published in the American Journal of Human Genetics. (ANI)
- 100-million-year-old gene mutation provides snapshot of evolution - Oct 19, 2010
- Scientists revamp genetic coding - Feb 15, 2010
- Major selective sweeps did not drive human evolution, says study - Feb 18, 2011
- The gut's 'friendly' viruses discovered - Jul 15, 2010
- New genetic risk factor for Lou Gehrig's disease identified - Aug 26, 2010
- How body recycles itself captured on camera - Sep 14, 2010
- Mouse genome offers human cancer clue - Mar 24, 2011
- How sickle haemoglobin protects against malaria - Apr 29, 2011
- Molecular switch to thwart Huntington's disease found - Dec 25, 2009
- Unique genetic adaptation helped our brain grow - Apr 13, 2012
- Scientists shed light on how bone's material flaws lead to disease - Aug 05, 2009
- Scientists crack genetic code for form of pancreatic cancer - Jan 21, 2011
- Mechanism affecting Salmonella virulence, drug susceptibility discovered - Jul 30, 2010
- 'Key player' that facilitates Parkinson's disease found - Mar 04, 2011
- Full genetic blueprint of blood cancer offers new insights - Mar 24, 2011
Tags: 20 amino acids, american journal of human genetics, ben gurion university, birk, brain atrophy, disease progression, dna sequence, epilepsy and mental retardation, genetic defect, genetic mutation, human genetic code, human tissues, journal of human genetics, molecular mechanisms, ohad, prenatal genetic screening, protein chain, proteins in the human body, screening test, stop codon