Biological and genetic basis of various human genetic disorders and the application of biological and genetic markers

The antigens of the ABO blood group systems are expressed on the membrane of the red blood cells and on the surface of several pathological and normal cells and tissues. Following this earlier investigations, the pathological state of genetic diseases and disorders were determined from the blood fluids and blood cells. Biology of most of the genetic diseases was associated with the development of marks and the ABO antigens were associated with the development of various tumours, namely gastric and pancreatic cancers. ABO antigens are used as the prognostic biomarkers in various types of cancers in human. Moreover, the association of these antigenic effects is uncertain. In human, several epigenetic marks required for the normal development. These include DNA methylation at GpG dinucleotides, noncoding RNAs and covalent modifications of histone. These functions are regulated in organized manner, regulating mitotically heritable changes in the expression of genes without changing the primary sequences of DNA. Any changes in the expression of these proteins due to genetic or environmental factors affect normal function and leads to aberrant epigenetic pattern. These aberrant epigenetic patterns lead to various human disorders, including imprinting and sub-fertility. The present review discusses the biology and genetics of various diseases and highlights the important theoretical and technical problems. Human genome sequences and other technical implications in the line of genetic diseases are discussed in this review.(c) 2022 The Author. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).