Abstract:
Introduction: The Azoospermia Factor c (AZFc) region of Y chromosome
undergoes de novo mutation and considered as a significant risk factor for
spermatogenic impairment which has been well distinguished in infertile and also
in fertile individuals with varied effect. However, the impact of these deletions on
etiology of male infertility remains poorly understood Indian heterogeneous
population. This AZFc sub deletions increase the risk factor of spermatogenic
impairment that results in infertile/sub fertile condition.
Objective: To investigate the correlation between the AZFc subdeletions and
spermatogenic phenotypes in admixed population of South India.
Methodology: We recruited the fertile normozoospermic (n= 250) and infertile
(n=250) individuals with age group ranging 20-45 years. Semen analysis with
sperm function test was performed as per the WHO protocol and five AZFc
specific sequence tagged site markers were employed to detect deletions in various
gene clusters in AZFc regions namely, DAZ (sY254,sY255), gr/gr (sY1291),
b1/b3 (sY1291, sY1197) and b2/b3 deletions (sY1191) by means of standard PCR.
Results: In comparison with other AZFc sub deletions we recorded a high
occurrence of gr/gr sub deletion (36.3%) in infertile (n=16) and b2/b3 deletion in
fertile (n=12) individuals. Interestingly, we have not observed any changes in
sperm count, motility, morphology and vitality among the fertile
normozoospermic group. In contrast, azoospermic and oligozoospermic
subconditions were predominant in infertile individuals with impaired sperm
motility, vitality, and volume. Our current investigation is in accordance with the
Han Chinese population study in China/East Asians and also among Japanese
population where they have recorded the positive association of gr/gr sub deletions
with spermatogenic impairment among infertile.
Discussion: There is a significant differences in the frequency of gr/gr deletions
between fertile and infertile groups but not for other AZFc subdeletions. Thus, the
Y chromosome AZFc gr/gr deletions result in spermatogenic impairment by
reducing the sperm quality. Further, screening of single nucleotide variant and loss
of specific gene copy in AZFc region and its effect on male infertility using RFLP
approach is in progress.
