Gene Terminology and Genetic Changes

Gene Terminology

• Locus: The location of a gene on a chromosome
• Allele: Different forms of a gene
• Gene: A sequence of DNA that codes for a protein or RNA molecule
• Homozygous: An individual with two identical alleles at a locus
• Heterozygous: An individual with two different alleles at a locus
• Hemizygous: An individual with only one allele for a particular gene, typically due to X-linked genes in males
• Wild-type: The most common allele in a population
• Variant: A version of a gene or allele that differs from the wild-type
• Reference Genome: A standard DNA sequence used for comparison

Genetic Changes

• Reference Genome: The latest version of the human genome reference is GRCh38, updated in February 2019
• Mutations: Changes in the DNA sequence that can occur at the base level or on a larger scale, affecting both somatic and germline cells
• Mutation Process: The process by which the DNA sequence changes

Gene Basics

• Locus: The specific location of a gene on a chromosome.
• Allele: Different versions of a gene or DNA sequence.
• Gene: A sequence of DNA or RNA that codes for a specific protein or RNA molecule.

Genotype Terminology

• Homozygous: An individual with two identical alleles at a locus.
• Heterozygous: An individual with two different alleles at a locus.
• Hemizygous: An individual with only one allele for a particular gene, usually due to an unpaired chromosome (e.g., males have one X chromosome).
• Wild-Type: The most common allele in a population, often referred to as the "common" allele. Avoid using "normal" as it can be misleading.
• Variant: A version of a gene or allele that differs from the wild-type, typically due to changes in the DNA sequence.

Reference Genome

• Reference Genome: A standard sequence used for comparison in genetic analysis. The human genome reference was first established in 2001 and is regularly updated (latest version: GRCh38, February 2019).

Mutations

• Mutation Process: Changes in the DNA sequence, which can occur at the individual base level (e.g., substitutions) or larger scales (e.g., chromosomal rearrangements).
• Mutations can affect: Somatic cells (body cells) or germline cells (cells that give rise to reproductive cells).

Gene Location and Alleles

• Locus: Position of a gene on a chromosome
• Allele: Different versions of a gene, with variations in DNA sequence
• Gene: Contains code for one protein or RNA molecule

Genotype and Allele Combinations

• Homozygous: Two identical alleles at a locus
• Heterozygous: Two different alleles at a locus
• Hemizygous: One allele present, typically for X-linked genes in males

Allele Types

• Wild-Type: Most common allele in a population, not necessarily "normal"
• Variant: Allele differing from the wild-type, often due to DNA sequence changes

Reference Genome

• Human Genome Reference (GRCh38): Updated in 2019, used as a standard for comparing genetic changes

DNA Sequence Alterations

• Mutation: Change in DNA sequence, occurring at the base level or on a larger scale
• Chromosomal aberrations: Large-scale mutations affecting chromosomes
• Somatic mutations: Occur in non-reproductive cells
• Germline mutations: Occur in reproductive cells, passed to offspring

Genetics Terminology

• Locus: The specific location of a gene on a chromosome.
• Allele: Different forms of a gene or DNA sequence - alternative versions of the same gene.
• Gene: A sequence of DNA or RNA that codes for a specific protein or RNA molecule.
• Homozygous: An individual with two identical alleles at a given locus.
• Heterozygous: An individual with two different alleles at a given locus.
• Hemizygous: Having only one copy of a gene in a diploid cell, typically for X-linked genes in males.
• Wild-Type: The most common allele in a population, typically referred to as the "common" allele.
• Variant: A version of a gene or allele that differs from the wild-type, often due to changes in the DNA sequence.
• Reference Genome: A standard against which genetic changes are measured. The human genome reference was first established in 2001 and updated in 2019 (GRCh38).
• Mutation Process: Changes the DNA sequence - occurs at the DNA level, or on a larger scale like chromosomal aberrations. Mutations can impact both somatic and germline cells.