Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences of Yazd
Abstract
Background: Mitochondrial transfer RNAs (tRNA) genes are essential
components of protein biosynthesis. These genes are hotspots for
mutations. These mutations are associated with a wide spectrum of human
disease. Many genetic factors are known in assessment of repeated
pregnancy loss (RPL). Objective: The aim of this study was analysis of
tRNA Thr and tRNA Pro in women with RPL. Materials and Methods: The
nucleotide variations of threonine and proline were investigated in 96
women with idiopathic repeated pregnancy loss. The related
mitochondrial area was amplified using a polymerase chain reaction
(PCR). The PCR products were demonstrated by 2% agarose gel
electrophoresis, and all the positive samples were purified and
verified by an automated DNA sequencing method. Results: The sequence
analysis revealed 4 mutations in tRNA Thr. These mutations were A15907G
in 2 cases (2.08%), A15924G in 3 cases (3.12%), G15928A in 10 cases
(10.42%) as the most common mutations and G15930A in 3 cases (3.12%) as
a novel mutation. Also, the result of tRNApro sequencing showed the
T15972C mutation in 1 woman (1.04%) as a novel mutation. Conclusion:
These tRNAs mutations can alter their steady state level and affect the
structure of tRNAs. It results in protein synthesis defects and, in
turn, mitochondrial dysfunction. The mutations of these genes may help
in the assessment of RPL. Further study of an expanded series of these
tRNA mutants is recommended to describe their etiologic role in
idiopathic RPL