Accurate measurements of a specific CAG repeat sequence in the Huntington's disease (HD) gene in 337 HD patients and 229 normal controls from the Scottish population showed a range from 35 to 62 repeats in affected subjects and eight to 33 in normal subjects. A link between early onset of symptoms and very high repeat number was seen. For HD patients with the most common affected allele sizes (...

Expansions of simple DNA repeats account for more than two dozen hereditary disorders in humans (for recent reviews see Lenzmeier and Freudenreich, Jin and Warren, Parniewski and Staczek, Ranum and Day, Brown and Brown, Cummings and Zoghbi, Bowater and Wells, and Siyanova and Mirkin). Table 1 describes those diseases and their important genetic features. Although originally discovered expansion...

Myotonic dystrophy (DM) is associated with an underlying CTG trinucleotide repeat expansion at a locus on chromosome 19q13.3. We have determined the repeat length in 23 DM patients with varying clinical severity of symptoms and various sizes of repeat amplification. We confirm that as in previous studies there is no strong correlation between repeat length and clinical symptoms but find that th...

Background s:648:"The infertility has recently been estimated to affect approximately 9% of couples worldwide. Androgens and a functional androgen receptor (AR) are essential for normal development of the male gender, and for maintenance of spermatogenesis throughout the life. Two polymorphic trinucleotide repeats, CAG and GGN, encoding for the amino acids glutamine and glycine, respectively ar...

background: expansion of gaa trinucleotide repeats is the molecular basis of friedreich’s ataxia (frda). precise detection of the gaa expansion repeat in frataxin gene has always been a challenge. different molecular methods have been suggested for detection of gaa expansion, including; short-pcr, long-pcr, triplet repeat primed-pcr (tp-pcr) and southern blotting. the aim of study was to evalua...

DNA repeat domains can form ensembles of canonical and noncanonical states, including stable and metastable DNA secondary structures. Such sequence-induced structural diversity creates complex conformational landscapes for DNA processing pathways, including those triplet expansion events that accompany replication, recombination, and/or repair. Here we demonstrate further levels of conformation...