THE KNOWN UK CASES OF ATAXIA TELANGIECTASIA-LIKE DISORDER (ATLD)

Abstract

Ataxia telangiectasia-like disorder (ATLD) is a very rare autosomal recessive disease with only 25 patients recognised worldwide. ATLD is likened to Ataxia telangiectasia (A-T) due to an overlap of clinical presentations and cellular characteristics. The clinical hallmark of A-T and ATLD is progressive young onset cerebellar ataxia. Variably present characteristics include dysarthria, oculomotor apraxia, ocular telangiectasia, immunodeficiency, spontaneous chromosome abnormalities and a predisposition to malignancy. In contrast to A-T, ocular telangiectasia is absent. Furthermore, ATLD patients tend to have a later onset and slower progression of neurological signs than A-T. The ATM gene, that has a key role in genome stability, is mutated in A-T resulting in an increase cancer predisposition. In ATLD, gene MRE11 is mutated leading to deficient activation of ATM. A functional consequence of the MRE11 mutation is raised chromosomal radiosensitivity because functional ATM kinase is required to rejoin chromosome breaks. This poster/presentation will describe the clinical features and genetic analysis of the ATLD cases with progressive ataxia known in the UK. Undergraduate Prize Winner 2015