Monday, May 31, 2010

Same Gotra Marriages

Love is superior to Gotra;
But Science has
something else to say
Writes Vinod Varshney
Nobody has the right to give death sentence to a loving couple, no matter they marry within the Gotra. “Love is superior to Gotra”, says Prof Neera Bhalla Sarin of Jawahar Lal Nehru University of New Delhi.

But Khap Panchayats have recklessly doled out death sentences in Haryana for such marriages. There is a demand from them to change the Indian Marriages Act also. Many consider this demand besmirched by medieval-thinking in modern times.

Today many especially from young generation do not even know what Gotra is. It is therefore natural that the controversy has puzzled so many. What does modern genetic science say on this issue?

Same Gotra Marriage Opposition has backing of Science : Chautala

In view of the genetic characteristics of Indian population, the demand has some scientific validity, says one of the most respected geneticist of the country Dr Lal Ji Singh, the former Director of Centre for Cellular & Molecular Biology, Hyderabad.

But his comments can easily be misinterpreted and perhaps are already being done by Navin Jindal, Congress MP and Om Prakash Chautala, Former Chief Minister of Haryana.

According to Dr Lal nothing bad can happen in one or two marriages within the same Gotra or Community. But if marriages keep on taking place in the same Gotra generation after generation then there is a risk of single gene diseases.

Will You Marry Within a Gotra: Navin Jindal

If two recessive genes, one from mother and the other from father, happen to join then the manifestation of single gene-specific disease is sure. So far more than 1,000 such diseases have been identified and include: cystic fibrosis, phenylketonuria (PKU), galactosemia, retinoblastoma, albinism, sickle-cell anemia, thalassemia, Tay-Sachs disease, autism, growth hormone deficiency, adenosine deaminase deficiency, and juvenile muscular dystrophy.

A study on this issue, led by scientists at the Centre for Cellular and Molecular Biology (CCMB) in Hyderabad together with US researchers at Harvard Medical School, the Harvard School of Public Health and the Broad Institute of Harvard and MIT was published in the September 24th issue of Nature. This study supports in a way the contention of those who are opposing the marriages within the same Gotra.

According to this study many groups in modern India descend from a small number of founding individuals, and could not get gene flow from other groups since then. This happened obviously because of marriages within the same caste and more so within the same gotra.

Restricted Gene-flow Has Created the Risk

This finding that a large proportion of modern Indians descend from “small number of founding individuals" means that India is genetically not a single large population. Instead it is best described as many smaller isolated population-groups. The populations have remained isolated because of marriages within castes.

Traditionally in Hindu society marriages do take place within the caste but marriages within Gotra (further sub-division of caste) is avoided. The study mentioned above is being cited now as the scientific basis to oppose marriages within the Gotra. If marriages take place within the same Gotra then the risk of Recessive Gene Disorder becomes higher. But it does not mean every such couple will give birth to a baby with the Recessive Gene Disorder.

Risk Only When Mother & Father Are Both the Carriers of Recessive Gene

If parents are of same caste and same gotra then there are enough chances that both are carriers of a recessive gene. Recessive Gene Disorder occurs only when the baby carries two malfunctioning copies of the relevant gene, one coming from mother and other from father.

The study mentions, “Allele frequency differences between groups in India are larger than in Europe, reflecting strong founder effects whose signatures have been maintained for thousands of years owing to endogamy (marriage within the caste). We therefore predict that there will be an excess of recessive diseases in India.”

Haldane wrote decades ago that ‘‘if inter-caste marriages in India become common, various… recessive characters will become rarer’’ that means only Indians will have that disease. An example is a 25-base-pair deletion in MYBPC3 that increases heart failure risk by about sevenfold, and occurs at around 4% throughout India but is nearly absent elsewhere.