Abstract Over 100 X-linked intellectual disability genes have been identified, with triplet repeat expansions at the FMR1 (FRAXA) and AFF2 (FRAXE) being causative agent in two of them. The absence FRAXE pathognomonic features hampers early recognition, delaying testing molecular confirmation. Hence, our laboratory uses a multiplex PCR-based strategy to genotype both FRAXA FRAXE. However, are mi...

A labeled peptide nucleic acid (PNA) antisense probe was used to study the spatial distribution of triplet repeats (CTG) in human myotonic dystrophy (DM) cells by high-resolution fluorescence in situ hybridization (FISH). It was found that transcripts containing triplet repeats were present as a number of discrete foci in the DM nuclei. Greater numbers of foci were visible with the PNA probe th...

The expansion of unstable trinucleotide CAG repeat polymorphisms of a number of genes causes several neurodegenerative disorders with decreased cognitive function, the severity of the disorder being related to allele length at the triplet repeat locus. While the effects of repeat length have been well studied in clinical samples, there has been little investigation of the effects of triplet rep...

Triplet repeat sequence instability is associated with hereditary neurological diseases and with certain types of cancer. Here we study one form of this instability, deletion of triplet repeats during replication of template (CAG)(n)sequences by DNA polymerases. To monitor loss of triplet codons, we inserted (CAG)(9)and (CAG)(17)repeats into the lacZ sequence in M13mp2 and changed one repeat to...

The term "junk DNA" has been reconsidered following the delineation of the functional significance of repetitive DNA regions. Typically associated with centromeres and telomeres, DNA repeats are found in nearly all organisms throughout their genomes. Repetitive regions are frequently heterochromatinized resulting in silencing of intrinsic and nearby genes. However, this is not a uniform rule, w...

Molecular diagnosis of Huntington disease (HD) is currently performed by fluorescent repeat-flanking or triplet-primed PCR (TP-PCR) with capillary electrophoresis (CE). However, CE requires multiple post-PCR steps and may result in high cost in high-throughput settings. We previously described a cost-effective single-step molecular screening strategy employing the use of melting curve analysis ...