Haemoglobin is said to be a complex protein molecule contained within the red blood cell. It can be formed in the developing erythrocyte in the bone marrow. Abnormal Hb which can aise as a result of abnormalities in the globin molecules of the haemoglobin includes Hb C,D,E,G,H,I,J,K and S.
Disorders may arise from this abnormal hb which brings us to the haemoglobinopathies which include the HbS (sickle Hb), this genetic defect is as a result of inheritance of a defective beta gene. If passed on to an offspring by a parent, the offspring becomes a carrier of the sickle cell trait, but if passed on by both parents, the offspring possesses the sickle cell disease.
Some laboratory investigations used in detecting sickle cell disease
2 Sickling test
3 Solubility test
Sickle cell disease is a common genetic condition that affects hemoglobin, and determination of a persons haemoglobin genotype plays a vital role in erradicating sickle cell disease in Nigeria, because individual with this disease and traits can be properly informed on the appropriate thing to do.
Sickle cell anaemia contributes the to equivalent of 5% of under-five deaths on the African continent, more than 9% of such deaths in West Africa, and up to 16% of under-five deaths in individual West Africa countries (WHO, 2005). Many also die before their reproductive age. Sickle cell anaemia poses serious health concern, especially in developing countries. Awareness on genetic understanding and screening is not a common practice and the diagnosis is usually made when it is presented with a severe complication.
Even when tragedies such as two or more miscarriages, still births, or children die in infancy, many at times doctors do not order a blood test to take a closer look at genetic make up of parents or refer them to a genetic counsellor. Therefore, the most important challenge is to raise the awareness on its causes and prevention through health education. In Nigeria, no genetic counselling clinic is known as at the time of this study. In many developed countries, genetic testing and genetic counselling have been commonly done to identify carriers.
Increasingly, genetics seems to provide the answer to the basis of disease and to offer insight into the status of the health of populations. Medical genetics offers genetic testing as a tool for diagnosis and through genetic counselling, individuals will be provided with an accurate understanding of genetic inheritance and what it means to be ‘at risk’.
The usefulness of genetic testing relates to the efficacy of disease prevention and the right of a person to know his or her own genetic heredity. This will bring about a substantial impact on health improvement. Genetic screening for personal health will provide information about the health and well being (not necessarily reproductive health) while in other cases it may be used for health related reproductive risks.
Testing for genetic disorder will also provide a person with relieve of the uncertainty of not knowing, especially when such a person has a previous record of any suspecting disease. For example, a family member is currently suffering from the diseases-infertility, miscarriage, still birth or early child mortality. It puts people concerned in a better position to make major life decisions and it will also benefit family members either now or in the future. Additionally, genetic testing has become a tool for parents to decide whether to have only affected and non-affected offsprings.
When genetic testing has been carried out to establish a diagnosis of hereditary or congenial diseases in affected patients with high accuracy, it is usually accompanied with genetic counselling. Genetic counselling will help establish a diagnosis of hereditary diseases in affected patients, take measures to alleviate the clinical manifestations of such disease, predict the probability of development of a disease in families/individuals not yet affected and possibly prevent it.