Using a modified Repeat Expansion Detection (RED) assay, that was optimized for individual oligonucleotides, unrelated individuals were systematically screened for maximal repeat sizes of each of the ten possible trinucleotide repeats. Cloned trinucleotide repeats were generated and used as standards for the detectability of single copy trinucleotide repeat fragments. When the size distribution...

Trinucleotide-repeat expansion diseases (TREDs) are a group of inherited human genetic disorders normally involving late-onset neurological/neurodegenerative affectation. Trinucleotide-repeat expansions occur in coding and non-coding regions of unique genes that typically result in protein and RNA toxic gain of function, respectively. In polyglutamine (polyQ) disorders caused by an expanded CAG...

More than fifteen genetic diseases, including Huntington's disease, myotonic dystrophy 1, fragile X syndrome and Friedreich ataxia, are caused by the aberrant expansion of a trinucleotide repeat. The mutation is unstable and further expands in specific cells or tissues with time, which can accelerate disease progression. DNA damage and base excision repair (BER) are involved in repeat instabili...

The primary genetic abnormality in myotonic dystrophy (DM) is an expansion of the CTG trinucleotide repeat on chromosome 19q. Recently, patients with similar clinical features, but without this genetic alteration, have been designated as proximal myotonic myopathy (PROMM). We describe two additional cases of PROMM, both of whom presented with clinical features suggestive of myotonic dystrophy. ...

Trinucleotide repeat disorders are a heterogeneous group of diseases caused by the expansion, beyond a pathogenic threshold, of unstable DNA tracts in different genes. Sequence interruptions in the repeats have been described in the majority of these disorders and may influence disease phenotype and heritability. Spinal bulbar muscular atrophy (SBMA) is a motor neuron disease caused by a CAG tr...

The human genome contains many simple tandem repeats that are widely dispersed and highly polymorphic. At least one group of simple tandem repeats, the DNA trinucleotide repeats, can dramaticallyexpand in size during transmission from one generation to the next to cause disease by a process known as dynamic mutation. We investigated the ability of trinucleotide repeats AAT and CAG to expand in ...