Genetic disease is a disease caused by a change in the DNA sequence from the normal sequence. The change can occur in all or part of the DNA sequence.
By Humaira Zeb
These changes can affect individual bases (A, T, C, G) or much larger pieces of DNA or even chromosomes. Genetic disorders can be caused by a mutation in one gene which may be known as a single gene disorder or by mutations in multiple genes which may be known as a multifactorial disorder. As we unlock the secrets of the human genome, we learn that almost all diseases have a genetic component. Some diseases are caused by mutations inherited from parents and present in an individual at birth, such as sickle cell disease. Others are caused by acquired mutations in a gene or group of genes that occur during a person’s lifetime. These mutations are not inherited from a parent, but occur randomly or due to environmental exposure (such as cigarette smoke). These include many cancers, as well as some forms of neurofibromatosis. A genetic disease can cause rare diseases.
The term “rare disease” describes a group of diseases whose prevalence is so low that they are considered an unrealistic therapeutic market in the absence of appropriate encouragement and support and too rare to be fully studied and properly managed by medical professionals. professionals. Rare genetic diseases frequently affect the nervous system with a chronic, progressive and degenerative pathology that excessively affects children. Rare diseases are defined by their prevalence rather than by unifying pathological or clinical features. These diseases are infrequent; the reality is that ∼6,000 rare diseases collectively affect approximately 300 million people worldwide.
As we know, the nervous system is a very complex organ that is responsible for performing different tasks such as receiving and processing sensory information and controlling highly composed behaviors that enable survival. Neurodegenerative disorders occur due to the weakening of neurons, leading to neurodegeneration and disabilities over time. Neurodegeneration is the progressive loss of structure and function of neurons in the central or peripheral nervous system CNS or PNS. Neurodevelopmental disorders include the following conditions such as mental impairment, learning disabilities, hearing and visual impairments, cerebral palsy, autism spectrum, attention deficit hyperactivity disorder, and neuromuscular disorders. Neurological diseases have a large number of causes, including metabolic, viral, epileptogenic and environmental. Many of the neurogenetic disorders are due to consanguineous marriages and these consanguineous marriages are most often concluded between first cousins. Cousin marriages are mostly done in Asian and Middle Eastern countries. The closer the biological relationship between the parents, the greater the likelihood that their offspring will be at higher risk of developing neurogenetic disorders, as their offspring could obtain two identical copies of recessive genes from their parents. Consanguineous marriages have an effect on the rates of congenital malformations, loss of reproduction and genetic diseases, most often autosomal recessive.
Consanguinity is called marriage or marriage between close relatives or biological relatives. Consanguineous marriages have been very common since the beginnings of mankind. According to a rough estimate, almost one billion (20%) of the world’s population live in communities with a preference for consanguineous marriages, mainly in Muslim countries in the Middle East, Africa and South Asia. At 65%, Pakistan has one of the highest rates of cousin marriage in the world, followed by India (55%), Saudi Arabia (50%), Afghanistan (40 %), Iran (30%), Egypt and Turkey (20%). ).
Pakistan, a multicultural country with diverse caste systems, has historically shown the highest prevalence of inbreeding. Consanguineous marriages are encouraged in the country for multiple reasons, for example, to strengthen inter-family ties between close family members, a preference for the same caste and status, fear of incompatibility or difficulty in finding the right partner outside the family, the security of being familiar with spouse and in-laws before marriage, restriction of socialization with the opposite sex, and financial limitations, especially for dowry.
Countries around the world have worked on the identification and prevalence of neurogenetic disorders. Pakistan is also one of these leading countries. Dr Muhammad Ilyas, a young geneticist from the Center for Omic Sciences, Islamia College University Peshawar, in collaboration with the Department of Bioengineering, University of Engineering and Applied Sciences, Swat, NIBGE Faisalabad and University College London, launched a project to explore the genetic architecture of neurological disorders in the Pakhtun population known as NeurOmics.
For this purpose, about 200 families have been identified in the rural areas of KP, of which about 55 families have been studied and are published in reputable journals. While the rest of the families are still in process for exome sequencing and functional analysis. Clinical screening of patients is carried out with the help of neurologists at local hospitals in Peshawar, Swat and Abbottabad. Characterizing rural families requires local research efforts. Once the genetic bases of these diseases are characterized, they are preventable. The NeurOmics project focuses specifically on rural populations to address these issues.
The team developed local training programs for public health and genomics research, including research capacity building, training and collaboration across the region. Their training program, the establishment of new multidisciplinary research collaborations, and the data and approaches they implement from this project will provide a national resource for Pakistani researchers, as well as facilitate genetic studies of all ethnic populations. national.
Researcher at the Center for Omic Sciences, Peshawar