The key difference between genetic and congenital disorders is that genetic disorders are a result of a defective gene or a chromosome abnormality at birth or after birth, while congenital disorders are abnormalities present before birth.
A gene is a segment of DNA that contains the instructions to produce one specific molecule in the body, usually a protein. Genes control biological activities, including embryological development, foetal growth, metabolism, personality, cognition, and proliferation. Chromosomes are the genetic material within the cell that bears the genes. Therefore, genes are found in chromosomes located within the nucleus. Genetic disorders occur due to abnormalities in the genetic material as the stage of germ cell or early embryo. Congenital disorders are those that are evident at birth or early infancy.
CONTENTS
1. Overview and Key Difference
2. What are Genetic Disorders
3. What are Congenital Disorders
4. Similarities – Genetic and Congenital Disorders
5. Genetic vs Congenital Disorders in Tabular Form
6. Summary – Genetic vs Congenital Disorders
What are Genetic Disorders?
A genetic disorder is a health problem associated with one or more abnormalities in the genome at birth or after birth. Mutation in a single gene (monogenic) or multiple genes (polygenic), or a chromosomal abnormality gives rise to genetic disorders. Polygenic disorders are the most common, and such mutations occur spontaneously before embryonic development or due to autosomal recessive and dominant inheritance. Such genetic disorders are classified as hereditary disorders. Genetic disorders are present before birth, and some produce birth defects. Some cancer syndromes such as BRCS mutations are also hereditary genetic disorders.
Figure 01: Autosomal Recessive Genetic Disorder
Single gene or monogenic disorders are a result of a single mutated gene. These disorders pass on to the subsequent generations. Monogenic disorders are of different types, such as autosomal recessive, autosomal dominant, X-linked recessive, X-linked dominant, and Y-linked disorders. Huntington’s disease and multiple hereditary exostoses are common autosomal dominant disorders, whereas cystic fibrosis, albinism, and sickle cell anaemia are common autosomal recessive disorders. Klinefelter syndrome and X-linked hypophosphatemic rickets are X-linked dominant disorders, and haemophilia A, Lesch-Nyhan syndrome, colour blindness, and Turner syndrome are X-linked recessive disorders. Y-linked disorders are typically rare, but they may cause infertility in males. Multiple gene or polygenic disorders occur due to effects in multiple genes along with lifestyle and environmental factors. Heart diseases, diabetes, cancers, multiple sclerosis, obesity, asthma, and infertility are common examples of polygenic disorders. Chromosomal disorders are a result of a missing, addition, or irregular portion of chromosomal DNA in a gene. Down syndrome is a common example.
What are Congenital Disorders?
Congenital disorders are structural or functional abnormalities present before birth. Such disorders result in disabilities that may be physical, intellectual, or developmental and range from mild to severe. Congenital disorders are of two types: structural and functional disorders. Structural disorders are abnormalities with the shape of the body or a part of the body. Functional disorders include metabolic and degenerative disorders. Congenital disorders also result from genetic and chromosomal disorders. Genetic and chromosomal disorders involve the inheritance of abnormal genes from the mother or father or mutations in a germ cell.
Figure 02: Congenital Heart Defects
Medications and supplements such as tetracycline, hormonal contraception, teratogenic drugs, sleep-inducing aids, and antiemetics on pregnant women also cause congenital disorders. Toxic chemicals such as carbon monoxide, nitrates, nitrites, fluorides, chlorides, and heavy metals also give rise to congenital disorders. Certain infections such as vertically transmitted infection, rubella, herpes simplex virus, toxoplasmosis, hyperthermia, and syphilis directly pass from the mother to the embryo, causing congenital disorders during pregnancy or childbirth. Main risk factors for congenital disorders include advanced maternal age, folate deficiency, alcohol consumption or smoking during pregnancy, diabetes, and pregnancy in older women. Congenital disorders are diagnosed by screening tests and prenatal tests. Neural tube defects, Down syndrome, and heart defects are common congenital disorders.
What are the Similarities Between Genetic and Congenital Disorders?
- Genetic and congenital disorders are hereditary.
- They are a result of genetic and chromosomal abnormalities.
- Down syndrome is common to both types.
- Moreover, both disorders vary from mild to severe.
- Molecular techniques can be used to detect both disorders.
What is the Difference Between Genetic and Congenital Disorders?
Genetic disorders are a result of a faulty gene or abnormal chromosome, and their potential exists at birth, while congenital disorders are abnormalities that exist before birth and may have an environmental or genetic influence. Thus, this is the key difference between genetic and congenital disorders. The term genetic means that it transmits from parents to offspring, while the term congenital indicates that a disease is present from birth. Therefore, genetic disorders are hereditary, but not all congenital disorders are hereditary.
The below infographic presents the differences between genetic and congenital disorders in tabular form for side by side comparison.
Summary – Genetic vs Congenital Disorders
A genetic disorder is a health problem associated with one or more abnormalities in the genome at or after birth. Congenital disorders are structural or functional abnormalities present at or before birth. So, this is the key difference between genetic and congenital disorders. Genetic disorders result from a mutation in a single gene (monogenic) or multiple genes (polygenic), or a chromosomal abnormality gives rise to genetic disorders. There are two types of congenital disorders: structural and functional disorders. Structural disorders are abnormalities with the shape of the body or a part of the body. Functional disorders include metabolic and degenerative disorders.
Reference:
1. “Genetic Disorders: What Are They, Types, Symptoms & Causes.” Cleveland Clinic.
2. “What Is a Congenital Disorder?” Pregnancy Birth and Baby.
Image Courtesy:
1. “2926 Autosomal Recessive Inheritance-new” By OpenStax College – Anatomy & Physiology, Connexions Web site. Jun 19, 2013. (CC BY 3.0) via Commons Wikimedia
2. “2009 Congenital Heart Defects” By OpenStax College – Anatomy & Physiology, Connexions Web site, Jun 19, 2013. (CC BY 3.0) via Commons Wikimedia
Leave a Reply