The androgen receptor (AR) has two polymorphic sites in exon 1, characterized by different numbers of CAG and GGC repeats resulting in variable lengths of polyglutamine and polyglycine stretches. Longer CAG repeats result in a reduced AR transcriptional activity, whereas the role of the GGC triplets is less clear. A relationship between decreased spermatogenesis and moderate expansion in the CA...

Expanded CAG repeat tracts are the cause of at least a dozen neurodegenerative disorders. In humans, long CAG repeats tend to expand during transmissions from parent to offspring, leading to an earlier age of disease onset and more severe symptoms in subsequent generations. Here, we show that the maintenance DNA methyltransferase Dnmt1, which preserves the patterns of CpG methylation, plays a k...

CAG/CTG repeat expansions cause over 13 neurological diseases that remain without a cure. Because longer tracts cause more severe phenotypes, contracting them may provide a therapeutic avenue. No currently known agent can specifically generate contractions. Using a GFP-based chromosomal reporter that monitors expansions and contractions in the same cell population, here we find that inducing do...

BACKGROUND Age-adjusted morbidity and mortality rates from coronary heart disease (CHD) are higher in men than in women. Androgens are suspected to be responsible for the male disadvantage. The genomic effect of androgens is mediated by the androgen receptor (AR), which has a polymorphic CAG repeat in exon 1. The number of repeats is inversely related to the transcriptional activity of the AR o...

Huntington’s disease (HD) is a neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the huntingtin (HTT) gene. Disease pathogenesis derives, at least in part, from the long polyglutamine tract encoded by mutant huntingtin. Therefore, considerable effort has been dedicated to the development of therapeutic strategies that significantly reduce expression of the mutant hunt...

Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the huntingtin (HTT) gene. Disease pathogenesis derives, at least in part, from the long polyglutamine tract encoded by mutant HTT. Therefore, considerable effort has been dedicated to the development of therapeutic strategies that significantly reduce the expression of the mutant HTT pro...

BACKGROUND In the R6/2 mouse model of Huntington's disease (HD), expansion of the CAG trinucleotide repeat length beyond about 300 repeats induces a novel phenotype associated with a reduction in transcription of the transgene. METHODOLOGY/PRINCIPAL FINDINGS We analysed the structure of polymerase chain reaction (PCR)-generated DNA containing up to 585 CAG repeats using atomic force microscop...

We recently reported an association between prostate cancer risk and polymorphisms in the prostate-specific antigen (PSA) and androgen receptor (AR) genes. The purpose of this study is to test whether these two polymorphisms, AR CAG and PSA ARE1, influence serum PSA levels in healthy men. Serum PSA and the two genotypes were assayed for 420 healthy men from a multiethnic cohort, and regression ...

Spinocerebellar ataxia type 3 (SCA3), also called Machado-Joseph disease (MJD), is one of the most common SCAs worldwide and caused by a CAG repeat expansion located in ATXN3 gene. Based on the CAG repeat numbers, alleles of ATXN3 can be divided into normal alleles (ANs), intermediate alleles (AIs) and expanded alleles (AEs). It was controversial whether the frequency of large normal alleles (l...