Meaning of genetic disorder
By the term “genetic disorder” we mean three different types of etiologies in human –
1. Monogenic – caused by change in a single gene, so the disease is caused by synthesis of altered proteins or cessation of synthesis of the specific protein from that gene
2. Polygenic – due to change in multiple genes, usually some complex interaction takes place to form the disease condition
3. Chromosomal – alteration of structure or number of chromosomes
Disorders of mitochondrial genes are also included in the above classification.
1. Till now more than 10,000 different monogenic disorders were diagnosed in human beings.
2. The number of polygenic disorders is numerous, simply because it’s a matter of permutation and combination
3. The genetic disorders that cause fetal death or abortion usually remain undiscovered ().
4. Genetic diseases are still being discovered, in recent years on an average more than 250 genetic diseases are discovered per year. So the number is continuously increasing.
So considering the above facts and figures we can conclude that the number of genetic diseases can’t be estimated at this point of time.
- “Scientists currently estimated that over 10,000 of human diseases are monogenetic” – WHO | Genes and human disease.
- Robbins and Cotran Pathologic Basis of Disease, Professional Edition-Saunders (2014)