BAK, BAX, and NBK/BIK Proapoptotic Gene Alterations in Iranian Patients with Ataxia Telangiectasia

Ataxia telangiectasia syndrome: moonlighting ATM

INTRODUCTION

Ataxia-telangiectasia (A-T) a multisystem disorder primarily characterized by cerebellar degeneration, telangiectasia, immunodeficiency, cancer susceptibility and radiation sensitivity. Identification of the gene defective in this syndrome, ataxia-telangiectasia mutated gene (ATM), and further characterization of the disorder together with a greater insight into the function of the ATM protein have expanded our knowledge about the molecular pathogenesis of this disease. Area covered: In this review, we have attempted to summarize the different roles of ATM signaling that have provided new insights into the diverse clinical phenotypes exhibited by A-T patients. Expert commentary: ATM, in addition to DNA repair response, is involved in many cytoplasmic roles that explain diverse phenotypes of A-T patients. It seems accumulation of DNA damage, persistent DNA damage response signaling, and chronic oxidative stress are the main players in the pathogenesis of this disease.

Investigation of tRNA and ATPase 6/8 gene mutations in Iranian ataxia telangiectasia patients

INTRODUCTION

Ataxia telangiectasia (AT) is a rare human neurodegenerative autosomal recessive multisystem disease. AT is the result of mutations in the AT-mutated (ATM) gene. ATM protein is required for radiation-induced apoptosis and acts before mitochondrial collapse. The tRNA genes are considered one of the hot spots for mutations causing mitochondrial disorders. Due to the important role of ATM in apoptosis and its effect on the cell cycle it might be possible that it has a central role in mtDNA mutations. On the other hand, the tRNA(Lys/Leu) gene and also ATPase6 and ATPase8 genes are important for many mitochondrial diseases and many causative mutations have been reported from these genes.

MATERIAL AND METHODS

In the present research, we performed mutation screening for these genes in 20 patients who were diagnosed with ataxia telangiectasia by a PCR sequencing method.

RESULTS

The results showed a significant level of mtDNA variations in AT patients. Among 20 patients in this study, 12 patients (60%) were detected with point mutations, among which 8 mutations (40%) belonged to the MT-ATP6 gene. There was probably a second effect of mtDNA mutations in AT disease and mtDNA plays a main role in establishment of AT.

CONCLUSIONS

MtDNA mutations might be responsible for the decline of mitochondrial function in AT patients. Mitochondrial investigation can help to understand the mechanism of damage in AT disease.