Infertility has been an increasing cause of concern among youngsters these days. Scientists say genetic factors play a vital role in both male and female infertility.
Genetic factors – chromosomal, Yq microdeletion and cystic fibrosis – are responsible for approximately 30% of cases of male infertility, according to Rima Dada, Professor, Laboratory for Molecular Reproduction and Genetics, Department of Anatomy, All India Institute of Medical Sciences, New Delhi.
She was here to attend a symposium on genetics organized by Jubilee Mission Medical College and Research Centre, Thrissur, recently.
“Infertility is now classified as a complex lifestyle disease. According to recent epidemiological studies, nearly one out of every 5 couples face problem in conceiving a child. Impaired fertility of male partner is the cause in approximately 50% of couples unable to conceive spontaneously. About 30% to 40% men in the reproductive age group have a qualitative or a quantitative defect in sperm production,” Dr. Dada noted.
Genetic fertility consultation is generally sought by couples with primary or secondary infertility, repeated pregnancy wastage, congenital malformations or previous child with a genetic disorder, according to scientists.
“We have been studying the genetic factors associated with male infertility among Indian men. Our earlier studies have shown that about 9.3% infertility among Indian men is due to the Y chromosome microdeletions. Further studies show that several autosomal; Y chromosomal and mitochondrial genes accounted for additional 21.3% of the genetic factors responsible for infertility among men,” she noted.
Female infertility
Genetic causes of female infertility include ovulatory disorders such as Kallmann syndrome, fragile X syndrome, as well as karyotype abnormalities, which are of great significance in structural abnormalities of reproductive tract, according to Dr. Hema Purandarey, Medical and Reproductive Geneticist and founder Director of the Centre for Genetic Health Care, Mumbai.
Research on genetic causes infertility is rapidly expanded over the last decade. The available genetic tests make it possible to evaluate all the four compartments of fertility – hypothalamus (The Master Switch), pituitary (for production and secretion of gonadotrophins), gonads (for production of sex steroids and gametes) and outflow tract (for Egression of gametes).
In addition, three generation family history helps in picking up the high-risk cases for genetic disorders, she pointed out.
Infertility can also be noted as a minor manifestation in many other genetic conditions, including galactosemia, mucopolysaccharidosis, Prader-Willi, cystic fibrosis, progressive external ophthalmoplegia, autoimmune polyglandular syndrome type I, ovarian leukodystrophy and Demirhan syndrome.
“Various molecular and cytogenetic tests are available to assist them. Benefits of assisted reproductive technology or option of prenatal diagnosis/ pre-implantation genetic diagnosis/pre-implantation genetic screening is opened for them in high risk cases,” Dr. Purandarey said.
Role of various lifestyle factors and how simple lifestyle interventions can impact reproductive health were also discussed in the symposium.