In Indian families it’s most often the woman is blamed among married couples not able to have children. This burden has been carried for generations by women.
It will be no longer so in the future.
According to new genetic research by a global consortia, led by the Hyderabad-based, CSIR-Centre for Cellular and Molecular Biology (CCMB). Men too suffer from infertility and are responsible for the couple not having children, they say.
In the study which assumes significance, the CCMB researchers have not just busted the popular myth but also shown that male infertility contributes to nearly 50 percent of the problem.
According to Dr K Thangaraj the lead investigator, “This study should be a reminder to the society that half of the infertility cases are due to problems in men. And many of them are due to genes that come from the parents, often mothers, of these men. It is wrong to assume a couple cannot bear children because of only the woman’s fertility”.
The growing rate of infertility among young couples in the country has also led to the rapid rise in Fertility Clinics and Assisted Reproduction Centres, especially in metros and cities. Here too, very often the female used to be the focus of review. However, there is a market shift with both the couple being screened and accordingly the problem addressed in recent years.
High rate and reasons for male fertility
Worldwide too, available data shows that one out of every seven couples are infertile. And, male infertility accounts for ~50% of these cases.
Among the several reasons for these high percentage of cases range from defects in the male reproductive system, deficiencies in semen quality, and hormonal imbalance, says a statement from the CSIR-CCMB.
“Injuries, infections, chronic illness, lifestyle choices and genetic factors can all lead to infertility in males. We, however, do not yet understand the details of how these parameters control fertility at the moment.” the researchers said.
Genes identified for infertility
The research team said, “We identified a total of eight genes (BRDT, CETN1, CATSPERD, GMCL1, SPATA6, TSSK4, TSKS and ZNF318), that were not known earlier for their role in human male fertility.”
From these genes, the researchers have characterized a mutation in Centrin 1 (CETN1), to understand how the changes at the molecular level affect sperm production. They demonstrated the impact of CETN1 mutation in cellular models and found that the mutation arrests cell division, causing insufficient sperm production.
Explaining further, Dr Thangaraj added that they have also identified variations (mutations) in these genes that cause impaired sperm production leading to male infertility. The quantity and quality of sperm is a major determinant in the outcome of reproduction.
Dr Thangaraj is presently Director of the DBT-Centre for DNA Fingerprinting and Diagnostics, Hyderabad.
The lead author of the study, Dr Sudhakar Digumarthi said, “We first sequenced all the essential regions of all genes (around 30,000 of them) using next generation sequencing in 47 well-characterized infertile men. We then validated the identified genetic changes in about 1500 infertile men from different parts of India”.
A Ph D student of CCMB, Sudhakar is at present scientist at the ICMR-National Institute for Research in Reproductive and Child Health in Mumbai.
Incidentally, genetic research on male infertility has been carried out for the past two decades by Dr Thangaraj’s group at the CCMB, which has a large formation undertaking studies on Population Genetics. Dr Lalji Singh, the late Director of the Lab and Thangaraj have published many scientific papers in prestigious, international journals.
Earlier studies have shown that about 38% males with infertility have specific regions missing or abnormalities in their Y chromosomes or mutations in their mitochondrial and autosomal genes.
The present, Consortia study focused on the cause of infertility in the rest of the cases which constitutes the majority of infertility-affected men. They have identified 8 novel genes that were defective in these men in India. The study has been published online in the journal Human Molecular Genetics.
Giving his perspective on the study and findings, the Director of CCMB, Dr Vinay Kumar Nandicoori said, “The genetic causes established in this study could be used as potential diagnostic markers for male infertility and development of improved management strategies for male infertility.”
The global consortia consisted of researchers from the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru; Institute of Human Genetics, University Hospital Düsseldorf, Heinrich-Heine-Universität, Germany; All India Institute of Medical Sciences, New Delhi; CSIR-Central Drug Research Institute, Lucknow; Institute of Reproductive Medicine, Kolkata; Indian Institute of Science Education and Research (IISER) Berhampur; Mamata Fertility Hospital, Secunderabad; DBT-Centre for DNA Fingerprinting and Diagnostics, Hyderabad.
Somasekhar Mulugu, former Associate Editor & Chief of Bureau of The Hindu BusinessLine, is a well-known political, business and science writer and analyst based in Hyderabad
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