Genetics For Kids - Terms, Disorders And Facts

Genetics For Kids

Image: Shutterstock

Jump To:

So, your little scientist is curious about why he resembles you or your husband? Does he ping you with questions about ancestry and genetics, and are you looking for some age-specific information to tell him more about the subject of genetics?
If you nodded along, then you should consider reading our post ‘genetics for kids’ here. Below, we look at how to tell your kids about genetics including the terms, disorders and some interesting facts.

What Is Genetics?

Genetics is the scientific study of hereditary traits. Heredity refers to the process of a parent passing certain characteristics to their offspring. These can be physical traits, behaviors, talents, abilities, diseases, etc [1].

A monk (from the present-day Czech Republic) named Gregor Mendel was the first person to study genetic patterns in pea plants in the 1850s [2]. He is considered the father of modern genetics [3].

Important Genetic Terms:

Here are some important terms related to genetics:

1. Genes:

Genes are a set of guidelines for your body’s growth. The cells in the body contain these guidelines or blueprints [4].

2. Chromosomes:

Chromosomes contain genes. In human bodies, each cell contains 46 or 23 pairs of chromosomes. These pairs are known as autosomes. One pair comes from the mother and the other one from the father. Two pairs are sex chromosomes (X and Y). The other 22 pairs are nonsex chromosomes. Males have ‘46 XY’ chromosomes, and females have ‘46 XX’ [5].

3. DNA:

Every chromosome contains Deoxyribonucleic acid (DNA), along with genetic information. The DNA is a long molecule in the shape of the twisted ladder. Each ladder rung is a combination of four different chemicals. These chemicals are guanine (G), adenine (A), cytosine (C) and thymine (T). These come in varied combinations in different cells to make specific proteins. Proteins are body’s building structures. For instance, these chemicals make hemoglobin, the protein in the blood [6].

4. Cell Division:

Cell division is when a parent cell division leads to two daughter cells. Mitosis is cell division that leads to new cells. Meiosis is the creation of sperm and egg cells through the cell division process [7].

5. Cell Division Errors:

Cell division errors can lead to an unequal number of chromosomes in an individual. Monosomic cells have a missing chromosome. Trisomic cells have an extra chromosome. The abnormal number of chromosomes (aneuploidy) in a person can mean inheriting serious genetic disorders. For instance, an extra number of chromosome 21 (trisomy 21) can lead to Down syndrome. Monosomy X can cause Turner’s syndrome [8].

[ Read: Science Facts For Kids ]

Genetic Disorders In Children

Genetic disorders characterize ailments that include certain kinds of birth defects, growth and developmental problems, chronic ailments, and sensory deficits due to gene abnormalities. It is rather important to seek medical assistance to diagnose and treat child genetic disorders effectively (9).

Types Of Genetic Disorders

There are four kinds of genetic disorders namely, single gene disorders, mitochondrial disorders, chromosomal abnormalities, and multi-factorial disorders.

1. Single Gene Disorders:

In gene pairing, the child inherits one copy of each gene pair from the mother and other from the mother. However, a mutation or a gene alteration results in absence or modification of a particular gene. Some of the prominent single gene mutation or single gene disorders in children include:

  • Autosomal Recessive: Sickle cell anaemia, cystic fibrosis, and phenylketonuria
  • Autosomal Dominant: Familial hypercholesterolaemia and Huntington’s disease
  • X-linked Recessive: Haemophilia, Duchenne muscular dystrophy
  • X-linked Dominant: Rare kind of rickets popular as hypophosphataemia or vitamin D-resistant rickets (10).

[ Read: Growth Disorders In Children ]

2. Chromosomal Abnormalities:

Genes contribute towards the formation of deoxyribonucleic acid or DNA. DNA strands result in a structure that we call chromosomes. A chromosome disorder results due to change in the number or structure of chromosomes. The alteration in chromosome occurs soon after conception, inheritance, or during the formation of sperm or egg. Some of the chromosomal abnormalities include chromosomal mosaicism and uniparental disomy in children (11).

3. Mitochondrial Disorders:

Mitochondria stimulate the production of an energy chemical popular as adenosine triphosphate (ATP) in every cell. Genes in mitochondria and nucleus of cell instructs every cell for the production of enzymes that are quintessential for the ATP production. Alteration of genes can adversely affect the production of enzyme and ATP. Some of the prominent mitochondrial disorders in children are as follows:

  • Brain And Spinal Cord Disorders: Deafness, seizures, intellectual disabilities, and vision problems.
  • Heart Problems: Irregular heartbeat problems and cardiomyopathy
  • Musculoskeletal System: Floppiness and poor muscle tone (12).

4. Multifactorial Disorders:

Multifactorial disorders result due to multiple genes or polygenic inheritance. Spina bifida and high blood pressure in kids are some of the examples of multi-factorial disorders (13).

The symptoms of genetic disorders in children differ from one to other. Some common genetic disorders include Unusually short or tall, unusually shaped eyes, sparse or brittle hair, Misshapen teeth, Stiff or loose joints, missing or extra teeth, ear abnormalities, excessive hair on body, stunted growth and development, and  unusual birthmarks (14)

Treating Genetic Disorders In Children:

There is no specific cure for childhood genetic disorders. However, certain effective, special therapies and medical assistance can help children to cope with the deficient growth and lead life independently and happily. Treatments may vary according to the genetic disorder. Some of the recommended treatments include Speech therapy, Occupational therapy, Medication, Behavioral and educational interventions, Participating in social activities, Diet and lifestyle change, and Surgery in extreme cases (15)

[ Read: Science Experiments For Kids ]

Interesting Facts About Genetics For Kids:

  • Gorillas, orangutans, and chimpanzees have 48 chromosomes [16]
  • The genetic makeup of humans differs by only 0.1%. The rest 99.9% is identical
  • Humans share 85% genes with mice.
  • Changes in DNA can occur due to radiation from the sun or some chemicals.
  • Genetic engineering is the process of changing an organism’s genetic makeup.

Genetic Predisposition:

  • Genetic predisposition refers to a person’s greater chances of developing a medical condition due to his genes. For instance, you have a genetic predisposition for a certain type of cancer, obesity or a heart disorder. You may not have it, but you are susceptible to it.
  • The chances of you getting this disease can further rise due to external and lifestyle factors such as exposure to radiations or unhealthy eating habit.

The Human Genome Project:

  • The Human Genome Project (HGP) was an international collaboration of scientists to map the human genome. The complete set of genes or DNA of an organism is called genome.
  • The goal of the HGP was to gain a complete understanding of the human genome. The human genome consists of 3 billion or more base pairs of DNA. This showcases the enormity of the project. The U.S. Department of Energy and the National Institutes of Health coordinated the research with other international teams based in different countries. The project was completed two years ahead of schedule in 2003.
  • The genome study has allowed scientists to identify sources of genetic disorders more easily than before. It has also allowed researchers to develop cures for many inherited diseases.

Genetics is a vast and fascinating subject. You can further satisfy your child’s interest in the subject through books, science models and relevant news. Is your child interested in the subject of genetics? How do you fuel/satiate his curiosity on the subject? Tell us below.

Recommended Articles:

Featured Image