Gene mutation linked to onset of Alzheimer`s, Parkinson`s and Huntington`s diseases

Washington: Researchers have revealed that a gene mutation responsible for the devastating neurological disorder known as Lesch-Nyhan syndrome may offer clues to the developmental and neuronal defects found in other, diverse neurological disorders like Alzheimer's, Parkinson's and Huntington's diseases.

The study provided the first experimental picture of how gene expression errors impair the ability of stem cells to produce normal neurons, resulting instead in neurological disease.

Lesch-Nyhan syndrome is caused by defects in the HPRT1 gene, known for its essential "housekeeping duties," among them helping generate purine nucleotides - the building blocks of DNA and RNA.

Mutations in the gene result in deficiencies in the HPRT enzyme, leading to defective expression of the neurotransmitter dopamine and subsequent abnormal neuron function.

Using mouse embryonic stem cells modified to be HPRT-deficient, Theodore Friedmann, MD, professor of pediatrics at the University of California, and colleagues discovered that the cells do not develop normally. Instead, they differentiate from full-fledged neurons into cells that resemble and partially function as neurons, but also perform functions more typical of glial cells, a kind of supporting cell in the central nervous system.

In addition, they noted that HPRT deficiency causes abnormal regulation of many cellular functions controlling important operational and reproduction mechanisms, DNA replication and repair and many metabolic processes.

"We believe that the neural aberrations of HPRT deficiency are the consequence of these combined, multi-system metabolic errors. And since some of these aberrations are also found in other neurological disorders, we think they almost certainly play some role in causing the neurological abnormalities in diseases like Alzheimer's, Parkinson's, Huntington's and possibly others," Friedmann said.

The study is published inthe journal PLOS ONE.