Human pathology

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Genes

human genes, gene. Johannsen, 1909.

Definition: A gene is an ordered sequence of nucleotides located in a particular position (locus) on a particular chromosome that encodes a specific functional product (the gene product, i.e. a protein or RNA molecule). It includes regions involved in regulation of expression and regions that code for a specific functional product. See gene expression, allele.

Human genome comprises between 20000 and 29000 genes.

Features

- housekeeping genes
- cancer genes

Pathology (genic anomalies)

- quantitative genic anomalies

- qualitative genic anomalies (genic mutation)

  • proteic loss of function
    • genic deletion
    • point mutation
  • genic activation (proteic gain of function)
  • fusion genes (fusion proteins)

Historics

The term coined by Johannsen (1909) for the fundamental physical and functional unit of heredity. The word gene was derived from De Vries? term pangen, itself a derivative of the word pangenesis which Darwin (1868) had coined.

See also

- cancer genes

References

- Carlson EA. Defining the gene: an evolving concept. Am J Hum Genet. 1991 Aug;49(2):475-87. PMID: 1867208