Introduction
Genetic disorders are the condition which arises due to mutations in an individuals’ DNA. It can be a point mutation or frame shift of nucleotides in a gene which makes its protein product nonfunctional to produce proper functioning. Many genetic diseases are multi-factorial—they are caused by mutations in several genes compounded by environmental factors. Some examples of these are heart disease, cancer, and diabetes. Genetic disorders can be passed from parents to offspring as the genetic information stored in DNA of germ cell is decoded in the DNA if there is some mutated gene in germ cell the disorder will be passed on to generation.
Chromosome abnormalities are a well-established cause of pregnancy loss. The most common are autosomal aneuploidy (~75%), followed by polyploidy (~13%), sex chromosome abnormalities (~8%) and structural imbalance (~4%) [1,2]. Trisomy of chromosome 21, 13, or 18 as well as sex chromosome aneuploidy account for 60-80% of abnormal fetal karyotypes detected in cultured amniotic fluid cells. There are several techniques which can detect the probability of genetic disorder in unborn.
It is now possible to sequence the entire genome of an unborn baby with only a sample of the mother's blood. This means that metabolic and immunologic disorders can be detected prior to delivery and treatment can be started immediately after birth. Amniocentesis, chorionic villus sampling (CVS), and Non-Invasive Prenatal Testing (NIPT) are few techniques which were employed to the detect disability, mutation in genes.
With the advancement of research newer advance technologies are also developed in clinical diagnostic domain. Several new techniques in diagnosis are NGS, RAD, FISH, QF PCR, MLPA and CGH array are discussed in this chapter.