DNA triplex structures in neurodegenerative disorder, Friedreich's ...

530 Moganty R Rajeswari
on the ethnic group from 1/60 to 1/100 (Bidchandani et al.
1998). The majority (>95%) of patients with FRDA are
homozygous for large expansions of a GAA triplet repeat
sequence (66–1800 triplets). Indian patients clinically diagnosed
for FRDA were also found to be homozygous for
(GAA) repeat expansion (Mukerji et al. 2000). The (GAA)
repeat in the normal Indian population shows a bimodal
distribution with 94% of alleles ranging from 7 to 16 repeats
and a low frequency (6%) of large normal alleles, indicating
low prevalence of FRDA in the Indian population. Despite
the fact that FRDA incidence is low, because if its severity of
the diseases and very low survival chances of the patients,
Frataxia challenges the treatment using gene therapy.
7.3 Circulating plasma DNA
Cell-free circulating plasma DNA is found in blood and
other body fluids like urine, amniotic fluid, etc. Plasma
DNA is present in very low quantities in healthy controls.
However, elevated levels are being reported in a number of
diseases and infections (Swarup and Rajeswari 2007).
Therefore, cell-free DNA in plasma has emerged as an
attractive tool in early prognosis of several human diseases.
Significantly high levels (p