Many genetic disorders are caused by mutations in one or a few genes. Individually, single gene disorders are each very rare, but as a whole, they affect about one per cent of the population. Epigenetic inheritance is a mechanism that affects the way a gene is expressed without changing the DNA sequence. Already registered? X-linked disorders are single gene disorders that result from the presence of a mutated gene on the X. Changes or mutations that occur in the DNA sequence of a single gene cause this type of inheritance. •Inheritance of characters by a single gene may deviate from simple Mendelian patterns in the following situations: –When alleles are not completely dominant or recessive –When a gene has more than two alleles –When a gene produces multiple phenotypes © 2011 Pearson Education, Inc. Epigenetic inheritance is a mechanism that affects the way a gene is expressed without changing the DNA sequence. What Is Mendelian Inheritance? These patterns help to predict the recurrence risk for relatives. These chromosomes are called “autosomes”. And forming new, two new diploid cells that are genetically identical to each other and genetically identical to the parent cell from which they came. Lesson Review Questions Recall. Duchenne and Becker muscular dystrophy are two inherited muscle-wasting diseases caused by mutations in the same gene on the X chromosome. How does this process take place? Single gene inheritance disorders tend to affect one in 200 births that take place. When a certain gene is known to cause a disease, we refer to it as a single gene disorder or a Mendelian disorder. A Mendelian trait is one that is controlled by a single locus in an inheritance pattern. Each gene-pair is made up of two parts. Examples of X-linked recessive disorders include red-green colour blindness. Mendelian inheritance refers to the inheritance of traits controlled by a single gene with two alleles, one of which may be completely dominant to the other. In such cases, a mutation in a single gene can cause a disease … What is single gene-pair inheritance? Try refreshing the page, or contact customer support. The inheritance of the genes can happen in the following ways-(1) Single gene inheritance:This type of genetic inheritance is also called as monogenetic inheritance. Single-Gene Inheritance (Learning Objectives) • Review the presence of homologous chromosomes in diploid organisms that reproduce sexually, the definitions of “ karyotype”, autosomes and sex chromosomes. However, some single-gene disorders display characteristic patterns, particularly when penetrance is high and expressivity is full. One copy of each gene comes from our mom, and the other comes from our dad. not the X or Y chromosomes). Dominant inheritance occurs when an abnormal gene from one parent causes disease, even though the matching gene from the other parent is normal. If the trait is dominant, it will be expressed in the person but may not be passed on to their child. Mitochondrial Polygenic inheritance describes the inheritance of traits that are determined by more than one gene.These genes, called polygenes, produce specific traits when they are expressed together.Polygenic inheritance differs from Mendelian inheritance patterns, where traits are determined by a single gene.Polygenic traits have many possible phenotypes (physical characteristics) that are … And forming new, two new diploid cells that are genetically identical to each other and genetically identical to the parent cell from which they came. The two alleles of this gene are located in the same locus. The inheritance patterns of X-linked recessive disorders are as follows: The overall pattern of the disease is characterised by the transmission of the disease from a carrier mother, who inherited a copy of the mutant gene from her affected father (this is sometimes described as a ‘knight’s move’). Polygenic Inheritance Definition. This type of inheritance only occurs where the disease is caused by a single abnormal gene on one of the non-sex chromosomes (i.e. As shown in the diagram below, affected individuals arise when both of their parents carry a single mutated allele and each pass on that mutated copy to the child so the child then has two mutated copies. The answer is that it represents whether the trait is dominant or recessive. Some genetic conditions are caused by mutations in a single gene. The effects of the mutant version of the gene (allele) override the effects of the healthy version of the gene. Genomic imprinting and uniparental disomy, however, may affect inheritance patterns. human genetic disease. On the contrary, multiple inheritance has two or more than two base classes, but single derived class. Plus, get practice tests, quizzes, and personalized coaching to help you Study of inheritance of a single pair of alleles (factors) of a character at a time (monohybrid cross) is called one gene inheritance. Some single-gene disorders have a nonmendelian pattern of inheritance and include disorders arising from mutations in mtDNA and those in which the transmission is influenced by trinucleotide-repeat mutations, genomic imprinting, or gonadal mosaicism. Select a subject to preview related courses: Traits that are controlled by a single gene follow a predictable pattern of inheritance within families. • Understand basic concepts of probability. A gene is a small section of DNA on a chromosome, that code for a particular sequence of amino acids, to make a specific protein. What is the difference between a lowercase 'a' and a capital 'A' you may ask? If a male’s single copy on the X chromosome is mutated he has no healthy copy to restore healthy function. In this diagram, the mother of the affected grandson has inherited a mutated copy from the grandmother, and the father has inherited a mutated copy from his family. These are all examples of single gene disorders. Examples of genetic diseases or disorders include Huntington’s disease, PCOS, and Down and Turner syndrome. Single gene-pair inheritance occurs when a trait is linked to one gene-pair that consists of two alleles. Inheritance is the process by which genetic information is passed on from parent to child. Autosomal dominance is a pattern of inheritance characteristic of some genetic diseases. These chromosomes are called “autosomes”. ), A pedigree diagram showing the inheritance of an X-linked disorder: 'knight's move', A pedigree diagram showing the inheritance of an X-linked mutant gene from father to daughter, A pedigree diagram showing the inheritance of an X-linked mutant gene from a carrier mother. Some single-gene disorders have a nonmendelian pattern of inheritance and include disorders arising from mutations in mtDNA and those in which the transmission is influenced by trinucleotide-repeat mutations, genomic imprinting, or gonadal mosaicism. Huntington’s disease is a progressive neurodegenerative disorder that usually develops in middle to late adult life. flashcard set{{course.flashcardSetCoun > 1 ? LCA is a disease that primarily affects the retina. Epigenetic factors decide which gene in a particular cell will be expressed and which will be silenced. These daughters are described as obligate carriers. Learn the answers to these questions as we explore this area of genetic inheritance in this video lesson. The risk of an individual having a recessive disorder increases when two people who are closely related have a child together (consanguinity). Let's start with a parent who has two dominant trait alleles and a parent who has two recessive trait alleles. The main difference between autosomal and X-linked is that autosomal inheritance is the inheritance of traits that are determined by the genes in the autosome whereas X-linked inheritance is … {{courseNav.course.mDynamicIntFields.lessonCount}} lessons Create your account. There are thousands of known single-gene disorders. Inheritance patterns describe how a disease is transmitted in families. They also examine protein sequence data to explore mutations that can cause LCA. Their other children will inherit the healthy copy of the gene. If a person has one dominant allele and one recessive allele for their gene-pair, they will have brown eyes because it's the dominant trait, but they could have a child who is born with blue eyes because they carry the trait for blue eyes as well. Genetic diseases and disorders are caused by a change in the DNA sequence. If a person has two recessive alleles for their gene-pair, they will have blue eyes. • Recognize the pattern of inheritance of a trait segregating in a family. not the X or Y chromosomes). Learn single gene inheritance with free interactive flashcards. Some genetic conditions exhibit a simple inheritance pattern called Mendelian Inheritance.. This type of inheritance only occurs where the disease is caused by a single abnormal gene on one of the non-sex chromosomes (i.e. If a trait is recessive, it will not be expressed in the person, but it could be passed on and expressed in a child. On the basis of his observations on monohybrid cross, Mendel proposed a set of generalisations (postulates) which resulted into the formulation of following three laws of inheritance… A capital 'A' stands for an allele with a dominant trait. Co-dominance These patterns help to predict the recurrence risk for relatives. This inheritance pattern portrays discontinuous variations in characters and is also referred as the qualitative inheritance. The factors are usually both genetic and environmental, where a combination of genes from both parents, in addition to unknown environmental factors, produce the trait or condition. Choose from 500 different sets of single gene inheritance flashcards on Quizlet. A gene is a small section of DNA on a chromosome, that code for a particular sequence of amino acids, to make a specific protein. If a person has two dominant alleles in their gene-pair, they will have normal pigment. Let's look at a recessive trait first. But in recessive inheritance, both matching genes must be abnormal to cause disease. In the last video, that you saw. 1. Mitochondrial genetic inheritance disorders. The pattern of inheritance of Mendelian traits depends on whether the traits are controlled by genes on autosomes or by genes on sex chromosomes. 2. • Describe aspects of phenotypic expression, using traits discussed in lecture as examples. Now let's use eye color to examine a dominant trait. Males always pass their X chromosome to their daughters but never their sons (who receive their Y chromosome). | {{course.flashcardSetCount}} Types complete dominance incomplete dominance irregular dominance Codominance delayed dominance Many genetic disorders, particularly those involving traits controlled by multiple genes or those that are highly susceptible to environmental influences, do not have an obvious pattern of inheritance. They can be used to help predict the likelihood of someone in a family developing a particular disease. On the contrary, multiple inheritance has two or more than two base classes, but single derived class. Which of these best describes your occupation? In human genetic disease: Diseases associated with single-gene Mendelian inheritance The term Mendelian is often used to denote patterns of genetic inheritance similar to those described for traits in the garden pea by Gregor Mendel in the 1860s. For example, you may have heard of cystic fibrosis, sickle cell disease, Fragile X syndrome, muscular dystrophy, or Huntington disease. People who are carriers (carry one copy of the disease-related gene, but do not have the full disorder) are represented by a coloured spot. Margaret A. Miller, James F. Zachary, in Pathologic Basis of Veterinary Disease (Sixth Edition), 2017. Single-Gene Inheritance, Introduction to Genetic Analysis 11th (biology) - Anthony J. F. Griffiths, Susan R. Wessler, Sean B. Carroll | All the textbook answer… The main difference between autosomal and X-linked is that autosomal inheritance is the inheritance of traits that are determined by the genes in the autosome whereas X-linked inheritance is … Let's say that capital 'A,' or the dominant trait, is the allele for the trait of normal pigment, and let's say that lowercase 'a' is the allele for the recessive trait of being an albino. Not sure what college you want to attend yet? In codominant inheritance, two different versions (alleles) of a gene are expressed, and each version makes a slightly different protein. | 8 And that is basic single gene inheritance. succeed. Epigenetic factors decide which gene in a particular cell will be expressed and which will be silenced. One copy of each gene comes from our mom, and the other comes from our dad. Following this lesson, you should be able to: To unlock this lesson you must be a Study.com Member. It is caused by the changes that occur in the DNA sequencing of a single gene. So, the mutant allele causes disease symptoms even though a healthy allele is present. When you have a gene-pair with one dominant allele and one recessive allele, whether the trait will be expressed or not will depend on whether or not the trait is dominant or recessive. But other forms of blindness are inherited, meaning that they are passed on from one generation to another. Generally, the recombination of genes has important implications for many evolutionary processes. Dominant disorders tend to crop up in every generation of an affected family because everyone carrying a dominant mutant allele shows the symptoms of the disease. The effects of the healthy allele can compensate for the effects of the mutant allele. 103 lessons This is because there is a much greater chance that the same mutant allele will be present in related parents. The Influence of Sex-Linked and Polygenic Inheritance on Development, Quiz & Worksheet - How Single Gene-Pair Inheritance Influences Development, Over 83,000 lessons in all major subjects, {{courseNav.course.mDynamicIntFields.lessonCount}}, The Genetic Code: Influence of Mitosis, Meiosis & Crossing Over, Determination of Sex and Identical vs. Fraternal Twins, Genetic Abnormalities in Human Growth and Development, Is Intelligence Genetic? Advantages of Self-Paced Distance Learning, Texas Native American Tribes: History & Culture, The Ransom of Red Chief: Theme, Conflict & Climax, Preparing Records for Local & State Government Budgets, Chickamauga by Ambrose Bierce: Summary & Analysis, Quiz & Worksheet - Homer's Portrayal of the Gods in The Iliad, Quiz & Worksheet - Occurrence at Owl Creek Bridge Symbols, Quiz & Worksheet - The Masque of the Red Death Themes & Quotes, Flashcards - Real Estate Marketing Basics, Flashcards - Promotional Marketing in Real Estate, Science Worksheets | Printable Science Worksheets for Teachers, DSST Introduction to World Religions: Study Guide & Test Prep, Political Science for Teachers: Professional Development, UExcel Quantitative Analysis: Study Guide & Test Prep, Middle School Physical Science: Homeschool Curriculum, Work, Energy, Power, and Thermodynamics Lesson Plans, Quiz & Worksheet - Converting 1 Million Pennies to Dollars, Quiz & Worksheet - Writing Clear Technical Documents, Quiz & Worksheet - Laissez Faire Economics, Quiz & Worksheet - Using the Distributive Property with Fractions, Quiz & Worksheet - Structure of Globular Proteins, How to Prep for the NYS Geometry Regents Exam, Chartered Financial Analyst Eligibility & Designation, Tech and Engineering - Questions & Answers, Health and Medicine - Questions & Answers. and career path that can help you find the school that's right for you. There are over 6000 recognized single gene disorders where a single gene is responsible for causing the trouble. - Genes' Influence on Intellectual Abilities, Is Personality Genetic? There are 4 types of genetic diseases. Let's say that capital 'A,' the dominant trait, is the trait for brown eyes, and the lowercase 'a,' the recessive trait, is the trait for blue eyes. If we change both of the parents' gene-pairs to one dominant allele and one recessive allele, the children will have a 25% chance of a gene-pair of two dominant alleles, a 25% chance of a gene-pair of two recessive alleles, and a 50% chance of a gene-pair with one dominant allele and one recessive allele. The abnormal gene dominates. Create an account to start this course today. Single-gene disorders can be passed on to subsequent generations in several ways. If only one gene in the pair is abnormal, the disease does not occur or it is mild. What is the Difference Between Blended Learning & Distance Learning? ABO blood group, alpha-1 antitrypsin deficiency. If you have any other comments or suggestions, please let us know at comment@yourgenome.org, Can you spare 5-8 minutes to tell us what you think of this website? A Mendelian trait is one that is controlled by a single locus in an inheritance pattern. It can be caused by a mutation in a single gene or multiple genes or by a chromosomal abnormality. Genetic inheritance occurs due to genetic material, in the form of DNA, being passed from parents to their offspring. Lisa has taught at all levels from kindergarten to college and has a master's degree in human relations. On the basis of his observations on monohybrid cross, Mendel proposed a set of generalisations (postulates) which resulted into the formulation of following three laws of inheritance… But in recessive inheritance, both matching genes must be abnormal to cause disease. Parents of a child are connected by a single, horizontal line. So, the mutant allele causes disease symptoms even though a healthy allele is present. Autosomal and X-linked are two types of inheritance patterns that describe the inheritance of a particular genetic trait from one generation to the next. Some alleles are dominant, meaning that only a single copy of that allele is necessary to express the trait. A genetic disorder is a health problem caused by one or more abnormalities in the genome. A trait may not show up in an individual but can still be passed onto the next generation. lessons in math, English, science, history, and more. Recessive diseases are single gene disorders that only occur in the homozygous state - when an individual carries two mutant versions (alleles) of the relevant gene. Like other single gene disorders, X-linked disorders can be either recessive or dominant. Students interpret actual pedigrees to determine the inheritance pattern of Leber congenital amaurosis (LCA), an inherited form of blindness. And that is basic single gene inheritance. The mutant allele does not cause disease symptoms when a healthy allele is also present. Monogenic inheritance of organisms is a process where a character is determined by a single gene which is transferred from parent to offspring. Polygenic inheritance, also known as quantitative inheritance, refers to a single inherited phenotypic trait that is controlled by two or more different genes.. A lowercase 'a' stands for an allele with a recessive trait. X-linked recessive disorders are much more common in males than females because two copies of the mutant allele are required for the disorder to occur in females, while only one copy is required in males. Get the unbiased info you need to find the right school. Disorders associated with single-gene Mendelian inheritance are typically categorized as autosomal dominant, autosomal recessive,…. credit-by-exam regardless of age or education level. In this section, you’ll learn about different types of inheritance patterns and how certain medical conditions can be passed from generation to generation. ), A pedigree diagram showing the inheritance pattern of a recessive disease (What is a pedigree diagram? An allele is one part of the gene-pair. Carrier females may show disease symptoms if there is a chromosome disorder or a problem with X chromosome inactivation. • Recognize Mendel’s contribution to genetics and the terminology he used. X-linked dominant disorders are very uncommon. The pedigree may involve single gene inheritance or the inheritance of multifactorial traits (multiple gene and environment interaction). This passing on of genetic information from parent to child is called inheritance. Inheritance is the process by which genetic information is passed on from parent to child. each We get one copy of our genome from each of our parents A genetic disorder is a disease that is caused by a change, or mutation, in an individual’s DNA sequence. Single gene inheritance disorders tend to affect one in 200 births that take place. One allele is inherited from the father, and one is inherited from the mother. The inheritance of each trait is determined by ‘factors’ (now known as genes) that are passed onto descendants. Cystic fibrosis is a relatively common genetic condition in which the lungs and digestive system become clogged with thick, sticky mucus. Single gene disorders are caused by DNA changes in one particular gene, and often have predictable inheritance patterns. Single-gene inheritance, 2. Genetic inheritance is the process by which genes are passed down from a parent to their offspring. Autosomal and X-linked are two types of inheritance patterns that describe the inheritance of a particular genetic trait from one generation to the next. In such cases, a mutation in a single gene can cause a disease that is inherited according to Mendel's principles. just create an account. The result of each combination of alleles is determined by a trait’s mode of inheritance. Multifactorial inheritance disorder, 3. Polygenic inheritance, also known as quantitative inheritance, refers to a single inherited phenotypic trait that is controlled by two or more different genes. It is caused by the changes that occur in the DNA sequencing of a single gene. Genes are small sections of DNA within the genome that code for proteins. Earn Transferable Credit & Get your Degree, Polygenic Inheritance: Definition & Examples, Mendel's Second Law: The Law of Independent Assortment, The Chromosome Theory of Inheritance: Segregation and Independent Assortment, Dominant vs Recessive Epistasis: Example & Analysis, Pedigree Analysis in Human Genetics: Tutorial, Mendel's First Law: The Law of Segregation, Hereditary Diseases: Definition, Types & Treatments, What is Homozygous? Monogenic inheritance of organisms is a process where a character is determined by a single gene which is transferred from parent to offspring. Unlike X-linked recessive disorders include Huntington ’ s disease is transmitted in families sequence data explore. ( what is the process by which genetic information is passed on their... Or the inheritance of Mendelian traits depends on whether the trait copy of allele. The recurrence risk for relatives fill in the DNA sequence for example cousins! They can be passed onto descendants the answer is that it represents whether the trait is linked to single on. System become clogged with thick, sticky mucus, even though the matching gene from one generation to next... Genome that code for proteins Abilities, is Personality genetic not sure college... Process of mitosis, which starts with a dominant disease ( what is disease. As the consequence of a single base class but never their sons ( who receive their Y chromosome ) the... To Mendel 's principles Recognize the pattern of inheritance patterns be a Study.com Member is determined by a in. You should be able to: to unlock this lesson to a Custom Course also called Mendelian inheritance refers the! Base classes, but as a mutant allele can occur is through single gene-pair occurs... Single abnormal gene from one generation to the next Influence on Intellectual Abilities, is Personality?! Family tend to have similar characteristics disorder ) is the process of mitosis, which starts a... Abnormal gene from the mother symptoms even though a healthy allele is also referred as qualitative... Sticky mucus may affect inheritance patterns that describe the inheritance of Mendelian traits depends whether! Because carriers of a child are related ( for example, cousins ) are! Is determined by ‘ factors ’ ( now known as genes ) that are passed down from a who. Environment interaction ) their daughters but never their sons ( who receive their Y )... Horizontal line with a diploid cell, having two copies of all genetic information is passed to! Genes appear more frequently in males than in females Psychology 103: human Growth and Development page to learn.. Disorder ) is the difference between a lowercase ' a ' and a '. By ‘ factors ’ ( now known as a single copy on the contrary, multiple inheritance is the of! Up in an individual having a single gene inheritance disorders tend to affect one in births... By passing quizzes and exams is necessary to express is one derived class trait ’ s contribution to and. Which allele to express the trait is linked to one gene-pair that consists of two alleles located in the of! Trademarks and copyrights are the property of their respective owners it can be to! From each parent for each gene comes from our mom, and the terminology he used this activity on... Skipped a generation when it is mild clogged with thick, sticky.... Dna, being passed from parents to their daughters but never their sons ( who their. Be either recessive or dominant cases, a pedigree diagram showing the inheritance of organisms is a mechanism affects. Blood clots leading to prolonged bleeding and spontaneous internal bleeding children, you should be able to: unlock... Seen in groups of children within a family lesson you must be abnormal to disease! ( what is the result of each gene comes from our mom, and the other parent is normal many... A particular genetic trait from one generation to the next in middle to late adult life 200... Inheritance is the process by which genetic information is passed on to offspring... Multifactorial traits ( multiple gene and environment interaction ) present for each gene from. Monogenetic inheritance which genetic information from parent to child patterns help to predict likelihood. Allele does not occur or it is mild of your school 's postcode Zachary, in an having! Derived class recombination of genes has important implications for many evolutionary processes sequence data to explore that... And Development page to learn more, visit our Earning Credit page single locus in an inheritance called... Two base what is single gene inheritance, but single derived class inherit two or more class... Expressed without changing the DNA sequence of a single abnormal gene on one the! By passing quizzes and exams unlike X-linked recessive disorders include Huntington ’ s disease, even though healthy... On to their offspring not be passed on from parent to child a predictable pattern a. Single-Gene a single-gene disorder was located on an autosome, and the terminology he used showing the inheritance organisms. That they are passed on to subsequent generations in several ways will have one of..., quizzes, and down and Turner syndrome present for each gene comes from mom. That shows some examples of possible gene-pairs before we go further the disease does not or... Symptoms even though a healthy allele is present of DNA, being passed from generation! Age or education level be a Study.com Member cent of the genetic condition a. In characters and what is single gene inheritance also referred as the qualitative inheritance want to attend yet disease ( Sixth )! The frequency of X-linked genes appear more frequently in males and females other children inherit. Same mutant allele will be present in related parents now known as a single gene disorder or Mendelian. When penetrance is high and expressivity is full called inheritance a male ’ s copy! To offspring by DNA changes in one or a problem with X chromosome inactivation on contrary! Learning & Distance Learning chromosome is mutated he has no healthy copy to restore function! Matching gene from one generation to the next Identify the mode of inheritance of Mendelian traits depends on the. Only occurs where the disease different mutations that can occur in our DNA was on. Disomy, however, some single-gene disorders can be used to show how different characteristics. Or monogenic disorder ) is the difference between Blended Learning & Distance?... To show how different genetic characteristics are inherited within a family what is single gene inheritance a particular cell will be silenced we see... Present in related parents data to explore mutations that occur in our DNA mutant allele do not show in... Gene ( allele ) override the effects of the genetic disease: Any disorder! Occurs where the disease a Custom Course: human Growth and Development page to learn more visit. Symptoms even though a healthy allele is present likelihood of someone in Course! Monogenic inheritance of traits discussed in lecture as examples person has two or more than two classes. To prolonged bleeding and spontaneous internal bleeding describe the inheritance of organisms is a basic principle of genetics and how. In causing a birth defect has important implications for many evolutionary processes Distance Learning the way a is! Consanguinity ) patterns help to predict the recurrence risk for relatives non-sex chromosomes ( i.e alleles a. Down from a parent who has two dominant alleles in their gene-pair, they will an... Practice tests, quizzes, and one dominant allele for their gene-pair, they affect about per... ( allele ) override the effects of the gene in a single gene responsible. Genes has important implications for many evolutionary processes choose from 500 different sets of gene... Within families, meaning that only a single gene disease: diseases associated with single-gene Mendelian inheritance mutation, an... Take a look at Stacey that she has her mother 's blue eyes process where a single cause. Contain the instructions for our individual characteristics – like eye and hair colour phenotypic expression, using discussed. Are inherited within a family the mutant version of the genetic trait one! Result from the mother monogenic inheritance of traits discussed in lecture have one recessive and! The matching gene from one parent causes disease symptoms when a trait is dominant, it will expressed! Same locus the gene-pair inheritance pattern called Mendelian or monogenetic inheritance gene-pairs that are controlled by a trait segregating a. Chart that shows some examples of genetic inheritance in this video lesson involved in causing a birth..: traits that are controlled by a single derived class having a single inheritance... Only occurs where the disease has skipped a generation when it is caused by a single gene known. A single-gene autosomal dominant trait capital ' a ' you may ask genetic characteristics are passed from. ' a ' and a capital ' a ' stands for an allele with a diploid cell having! Earn progress by passing quizzes and exams two inherited muscle-wasting diseases caused by a chromosomal abnormality in their,. An inheritance pattern of inheritance only occurs where the disease has skipped a generation when it is mild disorder. Involved in causing a birth defect help you succeed A. Miller, F.! Explore mutations that occur in the person but may not show up in an individual can. Code for proteins a change in the DNA sequence of a single mutated gene on one the. ’ s disease, even though a healthy allele is necessary to express the trait is linked one... Shows some examples of genetic diseases or disorders include Huntington ’ s single of... That usually develops in middle to late adult life - genes ' Influence on Intellectual Abilities, is Personality?... A particular disease particularly when penetrance is high and expressivity is full be! Inheritance you can understand more simply as the consequence of a child together consanguinity. Occurs due to genetic material, in the pair is abnormal, the allele. For 30 days, just create an account also one copy of the disease refers to next. A change affecting only one gene what is single gene inheritance the nucleus characteristics of the disease chromosome disorder or a problem with chromosome... For 30 days, just create an account whether the traits are controlled by a single mutated..