Through Preconception Counselling and Genetic Counselling, patients and families are informed about existing or possible genetic problems and how to deal with them

GENETIC Counselling is the process whereby an individual or a family is provided information about an existing or possible genetic problem. The purpose of this effort is to educate the patient about the genetic facts and issues relevant to their circumstances. The higher the patient’s general awareness and basic education level, the better will be his/her understanding of the counselling. A variety of information could be passed on verbally and through printed pamphlets about the specific problems faced by the individual couple.

Child birth remains a very special and happy occasion for a family while the birth of a malformed or an abnormal baby brings the opposite results. According to current literature, two to five per cent of all pregnancies produce babies with structural malformations and six to eight per cent are born with some sort of genetic aberrations which may or may not be recognised straight away. However the most common story remains the birth of an affected child in a family with no such previous incidence.

Theoretically speaking, all pregnancies could be said to be at risk of a genetic mishap during the developmental period, but the family where such an occurrence has happened is at a much higher risk of a repetition. There are numerous congenital abnormalities that have a tendency to recur. Certain families are at a higher risk of having such a mishap. The traditions of consanguineous marriage are an added though an avoidable risk factor. Preconception Counselling and Genetic Counselling enables patients and families to manage the numerous issues arising out of this socially and psychologically fraught area.

Amongst the most common risk factors are the contributors like advancing maternal age, race, ethnicity, and consanguinity and repeated intermarriages in the same family. All these factors place subsequent generations under genetically unfavourable trends and genetic vulnerability.

When a couple has had a genetically affected child, the parents usually seek the advice of a doctor to discuss the problem. In most cases, the inherited abnormality may be visible in the appearance or the behaviour of the child and can be easily diagnosed clinically. In certain cases, however, some investigations may be required. The genetic counsellor has the responsibility of providing the concerned parents with information about the disease, the genetic and medical implications of other disorders that may show up later, mode of inheritance, risk of recurrence in subsequent siblings, and the treatment and rehabilitation of the affected child. The possibility of prevention and family planning is another area which is discussed. Since genetic counselling directly concerns human misery, it can bring bad news and cause the listener psychological tension. The counsellor can help to make the bad tidings more acceptable and tolerable socially and psychologically.

Pakistan’s population carries a wide variety of genetic backgrounds. We have seen a large spectrum of genetic disorders. A substantial percentage of these disorders remain undiagnosed and unattended. The verdict, usually, is given by the general practitioner or whoever treats the child. Since most of these calamities are considered a result of nature, no further steps are taken to learn about them by the family. If the patient can afford to consult the relevant physician, the family learns more about the disorder. Public awareness about inherited disorders is limited. As soon as the child is diagnosed as genetically affected the discussion is closed and the topic avoided.

Certain genetic disorders may be suspected or even diagnosed during the pregnancy through Ultrasonography and special tests and procedures on the expectant mother and foetal tissues. If confirmed, such pregnancies may not be allowed to proceed further if the patient so feels.

The common and frequent consultations regarding disorders detected in children in our population in the past ten years at Aga Khan University Hospital are Beta Thalassemia, Mental Retardation, Generalized physical and mental handicaps, Cerebral Palsy, Downs Syndrome (Trisomy 21 Mongolism), Edwards Syndrome, (Trisomy 18) Trisomy 13, Muscular Dystrophies, Osteogenesis Imperfecta Achondroplasias, Congenital Adrenal Hyperplasia, Cystic fibrosis, Fragile X syndrome, Turner Syndrome and Klinefelter Syndrome. Metabolic disorders include a large range of essential Enzyme Deficiencies incompatible with life, and many other single Chromosomal and single gene disorders. The common presenting symptoms are a history of a long period of Infertility, recurrent Abortions or the birth of an affected child. A detailed family history and the examination of the child provide the physician with clues to proceed further with diagnosis management and appropriate genetic counselling.

Families that may be considered at higher risk of producing genetically affected babies can be picked up in preconception counselling. They can be grouped as follows:

* A couple who have had an affected sibling;

* History of an affected child in the immediate blood relations;

* Intermarriage in close cousins;

* Maternal age above thirty five years;

* History of recurrent abortions more than three;

* A long history of infertility;

* Exposure to radiations as a part of treatment;

* Past use of cytotoxic drugs.

In a large percentage no clue may be available as our pedigree analysis may remain incomplete and our medical record keeping far from desirable.

A very common genetic disorder prevalent in Pakistan is Beta Thalassemia. This disease is transmitted from the affected parents who are the carriers of the disorder but do not suffer severely from the disease itself. This disease runs in families and is inherited through the genes. If both parents are carriers, as is commonly the case if they happen to be first cousins, they are likely to pass on the diseased gene to their offspring simultaneously. The offspring will be affected with the major disease and will be severely anaemic and dependent on repeated blood transfusions for survival.

In addition, the growth and development of such a child remains far behind the normal. They are potentially vulnerable to all types of infections and various diseases. The transfused blood is rapidly destroyed in the body leaving by-products. The main one is iron, which is toxic to those organs where it is deposited, e.g. liver, pancreas, thyroid, myocardium, gonads etc., causing damage to the functioning capability of the organs involved. The available treatments are expensive, cumbersome and offer only temporary relief. Bone marrow transplant, a possible long- term relief, is highly expensive, full of risks and not available to the majority of sufferers.

If an affected couple produce a pregnancy, it is likely to be affected as well. Under these circumstances, the pregnancy must be subjected to antenatal genetic screening by highly specialised techniques which can determine the genetic status of the offspring. In every such pregnancy there are twenty-five per cent chances that the pregnancy will be affected with major disease. There will be a fifty per cent chance of the foetus being affected with the minor form of the disease and the likelihood of the foetus being totally free of the disease is also twenty-five per cent. Hence the results of the test are discussed with the couple and only the healthy pregnancies are advised to continue further.

Genetic counselling facility is available at the Aga Khan University Hospital, in addition to selective genetic and chromosomal testing for commonly prevalent disorders.