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DRD4

The DRD4 gene encodes the dopamine receptor D4, a member of the D2-like family of G protein-coupled receptors that respond to the neurotransmitter dopamine. D4 receptors belong to the broader dopamine system involved in cognition, motivation, reward, and emotion.

DRD4 is located on chromosome 11p15.5. The receptor is expressed in several brain regions with notable levels

D4 is a seven-transmembrane GPCR that predominantly couples to Gi/o proteins, leading to inhibition of adenylyl

A major source of DRD4 genetic variation is an exon III variable number tandem repeat (VNTR) in

In pharmacology, D4 receptors have been explored as targets for atypical antipsychotics, particularly clozapine, which shows

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in
the
prefrontal
cortex,
cingulate
and
other
limbic
areas,
hippocampus,
and
amygdala,
and
comparatively
lower
expression
in
the
striatum.
Its
distribution
supports
a
role
in
executive
function,
attention,
and
behavioral
regulation.
cyclase
and
a
decrease
in
intracellular
cyclic
AMP.
It
can
influence
ion
channels
and
other
signaling
pathways,
and
there
are
multiple
splice
variants
that
may
differ
in
signaling
properties
and
tissue
distribution.
the
coding
sequence,
with
repeats
ranging
typically
from
2
to
11.
The
4-repeat
(4R)
and
7-repeat
(7R)
alleles
are
common,
with
population
frequencies
that
vary
by
ethnicity.
The
7R
allele
has
been
associated
in
some
studies
with
novelty
seeking,
risk-taking,
and
attention-deficit/hyperactivity
disorder
(ADHD),
but
findings
are
inconsistent
and
effect
sizes
are
small.
Overall,
DRD4
associations
with
behavior
and
psychiatric
conditions
are
considered
modest
and
part
of
a
larger
polygenic
influence.
relatively
high
affinity
for
D4
compared
with
some
other
antipsychotics.
Clinical
relevance
of
DRD4
variation
for
drug
response
remains
an
area
of
ongoing
research.