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The Science of Genetics and Behavior. Why Genes Matter in Psychology. Genes help to define who an individual is inside and out. While non-genetic factors have a role to play, too, what...
- A gene is the basic unit through which genetic information is stored and passed between generations. Physically, a gene is a specific section of on...
- The genome is the entirety of the genetic material contained in an individual. Human DNA is estimated to contain between 20,000 and 25,000 genes. T...
- A chromosome is a structure within a cell nucleus that is made up of a long DNA molecule and proteins that provide support. Each human cell contain...
- In addition to visible traits like weight and eye color, psychological qualities such as personality traits (such as extraversion and agreeableness...
- People’s levels of risk for all major psychiatric disorders are determined partly by genetics. Estimates of how much variability in risk can be att...
- The pathway from genes to psychological dispositions and behavior is highly complex, but it runs through the brain: Genetic instructions influence...
- The phrase “nature vs. nurture” has been used as a shorthand for the question of how much a people’s inherent nature, or genetics, explain the diff...
- Chemical compounds can attach to genes, modifying their activity without changing the underlying DNA. These modifications are called epigenetic cha...
- There is no one gene that activates a particular psychiatric disorder or any other complex psychological trait. In fact, many genes interact to inf...
Sep 24, 2015 · A pervasive assumption in evolutionary psychology is that how we act is affected by the genes we carry. Is there good concrete evidence of this? Are our outcomes predetermined by our biology?...
Dec 20, 2023 · Gene dominance refers to the phenomenon where one allele, known as the dominant allele, masks the expression of another allele, known as the recessive allele, in a pair. To understand the concept of gene dominance, it is essential to grasp what a dominant gene is and how it influences traits.
Mar 26, 2024 · The traditional nature vs. nurture debate in psychology frames the question of whether it’s genes or the environment that determines your personal qualities, ranging from intelligence to ...
- Overview
- What does ‘autosomal’ mean?
- How do people inherit traits?
- Autosomal dominant vs. recessive inheritance
- Examples of autosomal conditions
- Testing for autosomal traits
- Questions to ask a doctor
- Summary
Autosomal inheritance is when a parent passes down a condition to a child via autosomes, a type of chromosome. In autosomal inheritance, a copy of a faulty gene from one parent can cause a condition in the child. The child will have 50% chance of inheriting the faulty gene.
Chromosomes are thread-like structures inside cells. They contain DNA, which tells the body how to grow and function.
Humans generally have 23 pairs of chromosomes. One pair determines a person’s sex. The other 22 are autosomes, which influence other aspects of development. If one or both parents have an altered autosome, their child will inherit it.
Whether this causes the child to have a genetic condition depends on the condition itself. In some cases, for a child to inherit a condition, both parents must carry the autosome that causes it. In other cases, a child can inherit a condition when only one parent carries the autosome.
Read on to learn more about autosomal inheritance, dominant and recessive types, and the conditions people can inherit via autosomes.
A note about sex and gender
The term “autosomal” refers to autosomes, which are a type of chromosome.
Humans have 23 pairs of chromosomes, 22 of which are autosomes. The remaining pair are sex chromosomes, which determine a person’s sex.
Autosomes consist of strands of DNA. DNA has regions known as genes, which tell cells how to grow and function. If a person has an autosomal condition, it means they have a health condition that has occurred as a result of a change in one of these genes.
Scientists have assigned each autosome a number that corresponds to its size. The largest autosome, chromosome 1, has 2,800 genes, while the smallest, chromosome, 22, has 750 genes.
People inherit genetic traits from their parents. This occurs during conception, when sperm from one parent joins the egg, or ovum, of another.
Each of these cells contains a full set of chromosomes and genes, which means that each person inherits two copies of both. These chromosomes and genes contain all the information necessary to create another human.
Sometimes, genes can change, producing a gene variant. Some of these changes are so minor that they do not affect the way a gene works. However, if the changes are large enough, they can affect a gene’s function and result in disease.
While inherited genes can influence health conditions, it is also possible for genes to change in the uterus while a fetus is developing. This can result in a child having a genetic condition even though there is no family history of it.
There are two main subtypes of autosomal inheritance: dominant and recessive.
Autosomal dominant means that inheriting a single copy of a gene variant is enough to cause the condition. In this scenario, a child has a 50% likelihood of inheriting the gene variant from one parent and having the condition.
In contrast, autosomal recessive means that, in order to have a certain health condition, a child needs to inherit two copies of the gene that causes it — one from each parent.
If both parents are carriers but do not have the autosomal recessive condition themselves, their child has a 25% likelihood of inheriting the condition.
In addition to these inheritance patterns, there are other ways people can inherit genetic diseases:
•X-linked dominant: These conditions stem from gene variants on the X chromosome, which determines sex. Males have only one X chromosome, so inheriting one copy of the variant gene causes the condition. In females, who have two X chromosomes, the symptoms may be less severe. Only females can pass on X-linked disorders.
Here are some examples of autosomal dominant conditions:
•Huntington’s disease, which causes the progressive breakdown of nerve cells in the brain
•achondroplasia, a condition that affects bone growth
•neurofibromatosis, which causes tumors to form on nerve tissue
•familial hypercholesterolemia, which is high cholesterol that a person acquires by inheriting a gene variant from one or both parents
Here are some examples of autosomal recessive conditions:
There are several ways to test for autosomal traits:
•Single-gene tests: These detect variations in one specific gene. Doctors may recommend one if they suspect that a person has a certain inheritable condition.
•Panel tests: These identify variations in many genes that affect a certain aspect of health. For example, one panel test may target genes that affect the nervous system, while another may assess genes that affect cancer risk.
•Large-scale genetic tests: There are two types of large-scale genetic tests. Genome sequencing examines a person’s entire DNA, not just the genes. Exome sequencing examines either all the genes in the DNA or only the genes related to someone’s medical condition.
Some tests look for genetic expression changes as well. In addition to being completely “on” or “off,” genes can have different levels of expression in different types of cells. Gene expression tests compare these levels in healthy and diseased cells.
In addition to gene tests, there are tests for chromosomal changes.
If a person suspects they or their child could carry the gene for an autosomal condition, they may wish to ask their doctor any of the following questions:
•What is my risk of having a genetic condition?
•Could a disease that runs in my family have a genetic cause?
•What is my risk of passing on a genetic condition to my child?
•Should I get genetic testing?
•If I want to have a baby, should my partner and I get genetic testing first?
Autosomal inheritance is a way for genetic conditions to pass from parent to child. It describes genetic variants that sit within one of the autosomes, which are a type of chromosome.
In autosomal dominant inheritance, a child needs only one copy of a gene variant to develop a condition. For this to happen, only one parent needs to carry the gene.
In autosomal recessive inheritance, a child needs two copies of a gene variant — one from each parent — to develop a condition.
Huntington’s disease, cystic fibrosis, and sickle cell anemia are examples of conditions with autosomal inheritance. If a person is concerned that they or their child may carry the genes for these conditions, they should speak with a doctor.
Dec 20, 2023 · Dominant and recessive genes are two types of genes that determine the expression of traits in individuals. Dominant genes are those that overpower or mask the effect of recessive genes, while recessive genes only manifest their traits when paired with another recessive gene.
People also ask
What are dominant genes?
What if one parent has a dominant trait?
What are dominant and recessive genes?
What happens if a dominant gene inherited a recessive trait?
Do dominant genes overshadow recessive genes?
Why are dominant traits more common than recessive traits?
Apr 27, 2017 · A dominant trait is an inherited characteristic that appears in an offspring if it is contributed from a parent through a dominant allele. Traits, also known as phenotypes, may include features such as eye color, hair color, immunity or susceptibility to certain diseases and facial features such as dimples and freckles.
