Complex diseases are the result of a complex interaction of genes and environmental influences, most of which are unknown. Although certain complicated diseases are highly heritable, most do not follow precise, well-defined inheritance models and are rarely caused by a single defective gene.
Complex Diseases
A mix of hereditary and environmental variables causes complex disorders. Finding the molecular pathways by which genetic variables influence phenotypic is tough in any scenario, but it’s even more difficult in the case of complex disorders because genetic factors in individuals which are affected may differ. Systems biology techniques, particularly network-based approaches, have emerged as valuable tools for understanding complex diseases in recent years. These methods are frequently based on understanding of functional or physical interactions between molecules, which are commonly represented as a network.
Genes and environmental variables have a key role in the development of complex diseases. Because complex diseases have a hereditary component, they are seen running in families, but the structure may be a little hazy. Alzheimer’s disease, heart disease, autism, multiple sclerosis, diabetes, Parkinson’s disease, osteoporosis, glaucoma, stroke, depression, arthritis, and cancer are just a few examples of complicated diseases.
Complex diseases, unlike single gene disorders, tend to run in families but lack clear-cut inheritance patterns, making it impossible to forecast a person’s chance of inheriting or passing on some of these diseases.
Complex diseases are difficult to cure because they might be affected by environmental and genetic causes.
Any complicated disease’s occurrence is assumed to be determined by a balance of hazards; nevertheless, if there are too many negative hereditary and environmental factors, the balance can be thrown toward disease.
Complex Diseases Examples
There are many examples of complex disease which are given here;
- Tuberculosis
- Lung cancer
- Asthma
Single nucleotide polymorphisms
SNPs, or single nucleotide polymorphisms, are alterations in the DNA code that affect only one letter.
The most frequent form of gene variation is single nucleotide polymorphisms (SNPs).
SNPs are found throughout the genome, with one per 300 nucleotides on average.
Many genetic alterations linked to complicated diseases have been discovered by looking for SNPs which occurred more or less frequently in persons with the disease than in people who do not have the disease. A genome-wide association study, or GWAS, is the name for this sort of research.
Network Biology Complex Disease
Disease co-occurrences can help illuminate the connection between external exposures and molecular level such as diet, lifestyle, and patient care, hence disease progression pattern of individuals with several diseases have recently gotten a lot of attention. They can also reveal information about the common and multifunction genes and pathways’ underlying network biology.
Pleiotropy, resilience, and rewiring are all important ideas in the study of comorbidity and network dynamics, and they should be considered together because they all contribute to an individual’s disease trajectory.
The non-idealized patient’s temporal disease progression can be characterised using paths in a multi-morbidity space, where each dimension correlates to a quantitative phenotype.
Dynamic network models may be built to explore complex disease progression, and with breakthroughs in high – throughput omics, single-cell technologies, and sophisticated analysis tools, they are becoming increasingly viable.
Confusion and conflicting language have limited the usability of network concepts. This can be managed by a clear demarcation of concepts, particularly in terms of context, which includes the precise determination of period, phenotype, and organisational level.
Challenges for complex diseases
The inability to understand complex diseases would be that the cause of sickness cannot be traced back to a single gene or gene variant, but rather to changes in a large number of genes in conjunction with lifestyle and environmental variables. This combination of environmental factors and genetic allows diseases to be divided into subgroups, or phenotypes, with varying responses to medical treatment.
Healthcare today has a limited capability that will further expand on complicated disease diagnostics on a molecular level and genetic, making tailored therapy challenging. As a result, there’s a higher chance of not responding to treatment and having negative side effects. It could also result in higher societal indirect expenses, such as greater sick leave. Care professionals can better identify and classify individuals using precision medicine, which combines genetic data with examination of, for example, proteins in blood, to more effectively determine the proper treatment and lifestyle advice for the right patient.
Treatment of Complex Diseases
Complex health-care treatment is a sort of long-term or ongoing therapy that is determined by the severity of problem, age, and other considerations.
Doctors may recommend medicine or therapy to help with symptoms, or they may send someone to a specialist like an occupational therapist, psychologist or speech-language pathologist.
Most cases will necessitate some type of person-centred treatment. This could happen at a hospital or another type of healthcare facility. The finest treatment for complex health problems, on the other hand, takes place in the patient’s own home.
Conclusion
A mixture of genetic disturbances, among other things, causes complex disorders. As a result, we do not presume that a particular genetic mutation is identified as the aetiology of a complicated disease. Cancer, diabetes, autism, coronary heart disease and obesity are just a few of the ailments that fall into this category. Despite the fact that other factors play a role in such disorders, the focus of this review will be on genetic reasons.