RCCX is a
multiallelic copy number variation
Copy number variation (CNV) is a phenomenon in which sections of the genome are repeated and the number of repeats in the genome varies between individuals. Copy number variation is a type of structural variation: specifically, it is a type of d ...
human
DNA locus
Locus (plural loci) is Latin for "place". It may refer to:
Entertainment
* Locus (comics), a Marvel Comics mutant villainess, a member of the Mutant Liberation Front
* ''Locus'' (magazine), science fiction and fantasy magazine
** ''Locus Award' ...
on
chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...
6p21.3.
Name
The RCCX abbreviation composed of the names of the genes
RP (a former name for ''
STK19
Serine/threonine-protein kinase 19 is an enzyme that in humans is encoded by the ''STK19'' gene.
This gene encodes a serine/threonine kinase
A serine/threonine protein kinase () is a kinase enzyme, in particular a protein kinase, that pho ...
'' serine/threonine kinase 19),
''
C4'', ''
CYP21'' and ''
TNX'').
Structure
The number of RCCX segments varies between one and four in a chromosome,
with the prevalence of approximately 15% for monomodular, 75% for bimodular, and 10% for trimodular in Europeans.
The quadrimodular structure of the RCCX unit is very rare.
In a monomodular structure, all of the genes are functional i.e. protein-coding, but if a module count is two or more, there is only one copy of each functional gene rest being non-coding pseudogenes with the exception of the ''C4'' gene which always has active copies.
Each copy of the C4 gene, due to five adjacent nucleotide substitutions cause four amino acid changes and immunological subfunctionalization,
can be of one of two types: ''
C4A'' and ''
C4B''.
Each C4 gene contains 41 exons and has a dichotomous size variation between approximately 22 kb and 16 kb, with the longer variant being the result of the integration of the endogenous retrovirus
HERV-K(C4) into intron 9.
The RCCX module is the most complex gene cluster in the human genome.
It is part of the major histocompatibility complex class III (
MHC class III
MHC class III is a group of proteins belonging the class of major histocompatibility complex (MHC). Unlike other MHC types such as MHC class I and MHC class II, of which their structure and functions in immune response are well defined, MHC class I ...
),
which is the most gene-dense region of the human genome, containing many genes that yet have unknown function or structure.
References
{{gene-6-stub
Chromosomes (human)
Genetics