Human genome
Complete set of human DNA sequences, including nuclear and mitochondrial genomes.
The human genome is the complete set of DNA sequences for each of the 22 autosomes and the two distinct sex chromosomes (X and Y), along with a small DNA molecule found within individual mitochondria. These are usually treated separately as the nuclear genome and the mitochondrial genome. The human genome includes both genes and various other types of functional DNA elements, as well as large numbers of transposable elements, endogenized viral DNA, non-functional pseudogenes, and simple, highly repetitive sequences.
- size
- Approximately 3.1 billion base pairs in the haploid reference genome
- protein_coding_genes
- Between 19,000 and 20,000
- non_coding_DNA_percentage
- About 98–99%
- repetitive_DNA_percentage
- Approximately 50%
- pseudogenes
- On the order of 13,000
- reference_genome_version
- GRCh38.p14 (July 2023)
Quick Facts
- Term
- GCA_009914755.4
- Ucsc Assembly
- hs1
Facts from the source article.
Lore & Background
In 2000, scientists reported sequencing 88% of the human genome, but as of 2020, at least 8% was still missing. In 2021, a genome from a hydatidiform mole cell line (without the Y chromosome) was reported. The human Y chromosome, consisting of 62,460,029 base pairs, was sequenced completely in January 2023. The current standard reference genome, GRCh38.p14 (July 2023), contains approximately 3.1 billion base pairs and represents a composite genome based on data from multiple individuals. Most human cells are diploid, containing about 6.2 billion base pairs. In 2023, a draft human pangenome reference based on 47 genomes from people of varied ethnicity was published.
Reader's Guide
The human genome serves as the fundamental blueprint for human biology, containing both protein-coding genes and a vast array of non-coding functional elements. Its sequencing has enabled the identification of genetic variants underlying disease, the study of human evolution, and the development of personalized medicine. The reference genome, though not representing any single individual, provides a standard for comparison. Significant differences among individuals (on the order of 0.1% due to single-nucleotide variants and 0.6% when considering indels) are considerably smaller than differences between humans and chimpanzees (~1.1% fixed single-nucleotide variants and 4% when including indels). The ongoing refinement of the reference and the development of a pangenome aim to capture more human biodiversity. The genome's organization—including introns, regulatory sequences, repetitive DNA, and pseudogenes—continues to be a subject of active research, with no firm consensus on the total amount of junk DNA.
Did You Know?
- The human reference genome contains somewhere between 19,000 and 20,000 protein-coding genes.
- About 98–99% of the human genome is non-coding DNA.
- Repetitive DNA sequences comprise approximately 50% of the human genome.
- The human Y chromosome, consisting of 62,460,029 base pairs, was sequenced completely in January 2023.
Frequently Asked Questions
What exactly is the Human genome?
It is the complete collection of DNA sequences found in a human cell, covering the 22 autosomes, the X and Y sex chromosomes, and a small circular molecule inside each mitochondrion. In its haploid reference form, this totals approximately 3.1 billion base pairs.
What are the Human genome's main functional 'powers'?
Alongside roughly 19,000 to 20,000 protein-coding genes, it contains regulatory DNA, transposable elements, endogenized viral sequences, approximately 13,000 pseudogenes, and repetitive sequences that together make up about half the total length.
What percentage of the Human genome actually codes for proteins?
Only about 1–2% of the sequence is devoted to protein-coding genes, while the remaining 98–99% is non-coding DNA that includes regulatory elements, repetitive sequences, pseudogenes, and other functional or non-functional regions.
Why is the Human genome so central to genetics and genomics?
It acts as the foundational reference for mapping inherited traits, understanding disease mechanisms, and developing personalized medicine and gene therapies. The current standard assembly is GRCh38.p14, published in July 2023.
How does the Human genome's 'story' keep evolving?
The reference is not static—GRCh38.p14 (July 2023) is the latest official assembly, and researchers continue to refine gene annotations, discover new functional elements, and catalogue the full spectrum of human genetic diversity across populations.
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