The Sunday Leader

Link Between Cousin Marriages And Health Problems

by Camelia Nathaniel

Child with thalassemia being given blood transfusion

A link between cousin marriages and health problems– including heart and lung problems, Harlequin ichthyosis or other Severe Skin disorders, Thalassemia and recognised syndromes such as Down’s – linked to genetic inheritance, has been observed in communities around the world.

When parents share a common ancestor, it is termed a ‘consanguineous’ relationship and there is an increased risk that they will both carry the same faulty gene variation. If  both parents have the same gene variation, there is an increased risk of having a child with a genetic condition.

The most common form of consanguineous relationship is between first cousins and in some societies, can account for a large proportion of relationships.

The reasons for promoting consanguinity in certain communities are mainly social and include:

Strengthening the family ties; retention of property within a family and ease of finding a suitable marriage  partner.

Since our genetic information is passed down to us from our parents and grandparents and so on, people who are blood relatives will share a greater

proportion of the same genes than unrelated people.

If parents are unrelated, their risk for having a child with a birth defect or disability is between 2% and 3%. However according to experts, if parents are first cousins, the risk is a little higher at 5% to 6%. This is due to the increased chance that they will both carry the same autosomal recessive mutation, passed down through the family.

Another severe condition that can result in Consanguineous Couples; Marrying a blood relation is Harlequin ichthyosis. It is a rare autosomal recessive disease of infants in which the baby is encased in a massive, horny shell of dense, plate-like scale (hyperkeratotic ‘cocoon’) with deep cracks (fissures), accompanied by contraction abnormalities of the eyes (ectropion), turning outwards of a lip (eclabium), and flattened ears. It is the most severe form of autosomal recessive congenital ichthyosis where the dermis to be around 10 times thicker than normal.

Recently two children suffering from this condition was reported in Sri Lanka from Meewagala Orubedhiwewa in Mahiyanganaya.

This brother and sister have severe facial mutations and the parents find it extremely difficult to provide the necessary medical care for them with the meagre earnings the father makes as a labourer.

During the New Year celebrations, having heard of these children’s plight, Minister Harin Fernando had visited these children and donated gifts for them in order to uplift their spirits. He had also promised to assist the parents in educating these children and with their medical needs. Another disease that has plagued many in Sri Lanka is Thalassemia, which can also be a result of blood marriages. According to Dr. Kavinga Nanayakkara the patron of the Lanka Thalassaemia Circle, it is an inherited genetic blood disorder. He explained that when two parents with Thalassaemia Trait ( half thalassaemics ) marry a Thalassaemia major child could be born. According to Dr. Nanayakkara, there are nearly 4000 Thalassaemic children and 500,000 Thalassaemia carriers in Sri Lanka

Thalassaemia Major children need blood transfusions monthly, from five months of birth onwards, lifelong. Due to complications from iron overload from these monthly blood transfusions they die at a very young age. The eldest child alive in the Eastern Province of Ampara is only 17 years ! Most die in their late twenties. . Up to now there has been no known cure.

Speaking to The Sunday Leader Dr Nanayakkara said that the main cure available today for Thalassaemia is Bone Marrow Transplantation (BMT) from matching donor siblings, invented in the 1980’s, by Prof. Guido Lucarelli, Director, Mediterranean Institute of Haematology, Rome, Italy. “When I met him in Rome in October 2012 he spoke of the possibility of setting up a bone marrow transplantation centre in Sri Lanka.

Although unknown in Sri Lanka, this treatment modality has been in existence in Europe for the last 30 years and in India for 15 years,” he added.

The government spends over Rs. 800,000/- per child annually, who will invariably die at a young age, only for medication and the annual drug bill costs Rs. 1700 Million.

However Dr. Nanayakkara said that in Sri Lanka the cases of Thalessemia is purely by chance and not primarily due to blood marriages. “While there are around 500,000 thalassemia carriers in Sri Lanka 99% of them are unaware that they have the abnormal gene. So by chance if someone with the abnormal gene marries another with the same condition (chances 1 in 40) then the result is that the child born to them will be full blown thalassemia patient and they will need blood transfusions every month.

The maximum age that a thalassemia patient has lived in Sri Lanka is 32 years. The reason for the early death is that the patient’s blood eventually carries excess iron and this gets deposited in the heart, liver, kidney etc and the patient could go into heart or kidney failure and other complications and they die early.  Here there is nothing to do with Consanguinity. It is by chance that you marry someone outside the family but who has this abnormal gene,” explained Dr. Nanayakkara. Sri Lanka has a thalassemia carrier rate of 1 in 40 individuals.

This works out to 500,000 thalassemia carriers. When two thalassemia carriers marry, a thalassemia major child could be born. Most are unaware of their carrier status. When asked how one finds out if they are a carrier of this abnormal gene that causes Thalassemia, Dr Nanayakkara said that in a child with thalassemia the haemoglobin level will drop drastically and they will become breathless. “Hence they will need monthly blood transfusions. The normal haemoglobin level in Sri Lanka is around 12-14 grams percent. But the thalassemia carriers will have it at around 10%. So anyone with a low haemoglobin level but appears normal and can function normally, must get their blood checked for this abnormal gene, and the blood test is called high performance liquid chromatography (HPLC). The problem is that the HPLC blood test is expensive and therefore its difficult to ask a normal person without any symptoms to check their blood for HPLC.”

Explaining what Sri Lanka has done so far to combat thalassemia he said that having been in charge of the maternity ward at the Kurunegala hospital in around 2002, he had got interested in this condition as the thalassemia ward was just next to the maternity ward.

“I have worked with thalassemia patients and now we know that it can be cured through bone marrow transplant from a compatible sibling. In 2012 I met the person in Rome, who had done around 1500 such bone marrow transplants in Italy.

Then after my return we formed this society called the Lanka Thalassemia Circle, with around 2000 families. We tried to get this bone marrow transplant to Sri Lanka but the cost per child for this operation would be around Rs. 4.2 million. There was a consultant from Italy called Dr. Lawrence Falkner who came to Sri Lanka and we held discussions with him.

We also had to send the swab samples abroad for testing to see if these children were genetically compatible siblings for the transplant as genetic compatibility cannot be done here. We collect the samples from 100 children and their siblings to New York. Then only about 13-14 of them match completely. Each month we send around 100 swabs and so far we have sent around 800.

Now we have set up the bone marrow transplant at two private hospitals and we are trying to set up such bone marrow transplant facilities in the government health sector too.


1 Comment for “Link Between Cousin Marriages And Health Problems”

  1. Younas Gangow

    learning full article

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