Infertility involved in the genetic control of spermatogenesis

Infertility is
one of the most common disorders seen in medical practice worldwide. It is
defined as the inability of a couple to conceive after 1 year of unprotected
sexual intercourse. The number of infertile couples in the general population
is increasing and the recent studies show that about 15 to 20 % of couples in
their reproductive age are unable to have their own child is presenting an almost unsolvable
challenge to the health service. Infertility is a
problem of immense importance due to its social, emotional and religious
nature. Furthers more it exhausts the couple psychologically, socially, and
also drains their financial resources. 1,2.

      Due to increased number of infertility
centers, the diagnostic and therapeutic facilities are coming within the reach
of these infertile couples and can be easily helped by the use of assisted
reproduction techniques. Even, Intrauterine Insemination (IUI) and
Intracytoplasmic Sperm Injection (ICSI) by using the donors semen has received
tremendous acceptance by these infertile couples. The practice of using ICSI
technique by these severely infertile men carries the risk of passing on
genetic disorders to their children including chromosomal abnormalities 2,3.

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      Chromosomal abnormality is one of the
important causes of male infertility because it disrupts genes which are
involved in the genetic control of spermatogenesis can leads in to abnormal
semen parameters like non- obstructive azoospermia or sever oligozoospermia
with asthenozoospermia or teratospermia or both oligo-astheno-teratozoospermia.
The most frequent chromosomal abnormalities found in infertile men are
translocations and sex chromosome abnormalities. The impact of chromosomal
abnormalities on male infertility is very high and inversely related to the
sperm count. Major chromosomal abnormalities found with the range of 2.6 – 16.5
% in infertile men compared to the incidence in normal male population 0.3 –
0.4%; in which azoospermia are with high frequency from 11.6% – 23.8%,
oligozoospermia the incidence is 2.3 – 6.6 % while in severe oligozoospermia it
is about 10.4% 3,4,5. Chromosomal abnormalities can be easily diagnosed after
performing G banding using trypsin and Giemsa (GTG) karyotyping. Therefore,
karyotyping study is definitely a mandatory test in the diagnostic center of
any infertile male 5,6,7.

      Polymorphic chromosomal variants also have
been well studied both in the normal population and in infertile males.
Polymorphic variations are known to occur in the general population. However, higher
frequencies of these variants have recently been reported in infertile and
subfertile individuals, compared with normal population. Increased rates of
chromosomal polymorphic variants have been shown to be associated with poor
spermatogenesis 6,7.

       Therefore, the present study was undertaken to
find out the frequency and types of chromosomal alterations; major chromosomal
abnormalities and polymorphic chromosomal variants in infertile males and to
show the importance of cytogenetic screening of such patients prior to the use
of Assisted Reproduction Technique (ART), it is important to prevent them being
passed on to their children. This is of particular importance when
abnormalities are found in the Y chromosome, as they will be passed on to any male
offspring.