A genetic disorder is a genetic problem caused by one or more abnormalities in the genome. Most genetic disorders are quite rare and affect one person in every several thousands or millions.Genetic disorders may be hereditary, passed down from the parents’ genes. In other genetic disorders, defects may be caused by new mutations or changes to the DNA.Genes are the building blocks of heredity. They are passed from parent to child. They hold DNA, the instructions for making proteins. Proteins do most of the work in cells. They move molecules from one place to another, build structures, break down toxins, and do many other maintenance jobs.
Single Gene Disorder – When one specific gene is known to cause a disease it is known as single gene disorder. It is also called Mendelian disorder. Single gene disorders are not very common. Inheriting just one copy of the mutated gene is enough to have this disorder.Some examples of single gene disorders are sickle cell disease, muscular dystrophy, cystic fibrosis.
Chromosomal Abnormalities – It is a type of genetic disorder in which chromosomes or parts of the chromosomes are missing or altered. Chromosomes are the structures that bind the genes together. Chromosomal abnormalities can occur in a number of ways such as changes in the number of chromosomes, changes in the structure of chromosomes or how the chromosomes are inherited.Examples of chromosomal disorders include Down syndrome, Turner Syndrome, Williams Syndrome, Klinefelter Syndrome, CRI-DU-CHAT Syndrome.
Multifactorial Disorders – Multifactorial disorders are also known as complex disorder because they involve mutations in multiple genes coupled with lifestyle and environmental causes. Multifactorial or polygenic inheritance involves complex traits that are determined by various genes at different loci, and the effects of those genes are cumulative. Some examples of multifactorial disorders are breast cancer, ovarian cancer, colon cancer, Alzheimer’s disease, hypothyroidism, coronary heart disease, diabetes mellitus, osteoporosis, asthma, gout.
*Symptoms Of genetic disorder:
- Ear abnormalities
- Unusually shaped eyes
- Different colored eyes
- Facial features that are unusual or different from other family members
- Brittle or sparse hair
- Excessive body hair
- White patches of hair
- Large or small tongue
- Misshapen teeth
- Missing or extra teeth
- Loose or stiff joints
- Unusually tall or short stature
- Webbed fingers or toes
- Excessive skin