Articles

Marriage in relation hits kids' hearing

By Ms. Saritha Raju : Speech and Language Pathologist and Audiologist

India present a unique population structure which is not only of diverse ethnic constitute but also of contrasting cultural elements, particularly pertaining to the field of marriage. Population of India is divided by religion, language, region, caste and creed which are a composition of many sub population with consanguineous marriage norms.

Consanguinity is the tradition of marriage between immediate relations. In other words, a consanguineous mating is one between two individuals who have one or more common ancestors. This system of marriage is legally barred in many countries although uncle-niece marriages are common in Asian countries and first-cousin marriages are legal in many Western and Asian countries. It is a preferred pattern of marriage over large parts of the world because of legal and property right. Apart from this, it greatly strengthens the position of a woman if her husband’s family is bond. Thus consanguinity is a beneficial pattern for millions of couples though with a genetic price to pay for it. A survey done in the year 1992-93 found that the percentage of consanguineous marriage in India was 11.9 having highest percentage in Andhra Pradesh and least in Mizoram.

There is increased chance of having health and developmental problems directly due to shared inherited genetic information in children of related parents compared to non related. Different types of genetic disorders that have been reported to be common among children born of consanguineous marriage are congenital hearing loss, mental retardation, congenital heart defects, visual defects etc. Everyone carries genes that are mutated in some way The changes or mutations could be potentially harmful only if an individual have two copies of same mutated gene. Generally, two unrelated people will not have same mutated genes; hence children of unrelated parents are at low risk than related parents whose genes are shared to a greater proportion.

The world wide prevalence of profound, congenital hearing impairment is 11 per 10,000 children and is attributable to genetic causes in at least 50 percent of the cases. The percentage of consanguineous marriages in Andhra Pradesh is 22.36 but the rate of deafness in children born out of such wedlock is 41.73 percent. Speech, language and hearing disorders are increasing in numbers due to this kind of mating.

A study carried out by me under the guidance of Mrs. Priya James in the year 2004, to know the incidence of consanguinity in speech, language and hearing disorder from Rehabilitation Institute in Andhra Pradesh. The study included 1201 cases and the results showed that cases with delayed speech and language, hearing loss, mental retardation had higher percentage of consanguinity factor and least percentage were for the cases like stuttering, misarticulations, autism and other syndromes. Out of 1201 cases studied 9.9% of disabled cases were due to consanguinity as the most possible factor.

We need to increase awareness about the problems related to consanguineous marriages. Though inbreeding level had declined in most parts of India, it is still highly practised and favoured in states like Andhra Pradesh, Tamil Nadu, Karnataka, Kerala and Maharashtra. If proper guidance and awareness were given, this 9.9% could have been avoided. If this practice continues for the next 5 years in the same manner, the disabled population of India will increase considerably due to consanguinity factor.