''LRRTM1'' is a brain-expressed imprinted gene that encodes a leucine-rich repeat transmembrane protein that interacts with

neurexin Neurexins (NRXN) are a family of presynaptic cell adhesion proteins that have roles in connecting neurons at the synapse. They are located mostly on the presynaptic membrane and contain a single transmembrane domain. The extracellular doma ...

s and

neuroligin Neuroligin (NLGN), a type I membrane protein, is a cell adhesion protein on the postsynaptic membrane that mediates the formation and maintenance of synapses between neurons. Neuroligins act as ligands for β-neurexins, which are cell ...

s to modulate synaptic cell adhesion in

neurons A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. ...

. As the name implies, its protein product is a

transmembrane protein A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequentl ...

that contains many

leucine rich repeats A leucine-rich repeat (LRR) is a protein structural motif that forms an α/β horseshoe fold. It is composed of repeating 20–30 amino acid stretches that are unusually rich in the hydrophobic amino acid leucine. These tandem repeats commonl ...

. It is expressed during the development of specific

forebrain In the anatomy of the brain of vertebrates, the forebrain or prosencephalon is the rostral (forward-most) portion of the brain. The forebrain (prosencephalon), the midbrain (mesencephalon), and hindbrain (rhombencephalon) are the three prima ...

structures and shows a variable pattern of maternal downregulation ( genomic imprinting).

Clinical significance

''LRRTM1'' is the first gene linked to increased odds of being

left-handed In human biology, handedness is an individual's preferential use of one hand, known as the dominant hand, due to it being stronger, faster or more dextrous. The other hand, comparatively often the weaker, less dextrous or simply less subject ...

, when inherited from the father's side. * Possessing one particular variant of the LRRTM1 gene slightly raises the risk of

psychotic Psychosis is a condition of the mind that results in difficulties determining what is real and what is not real. Symptoms may include delusions and hallucinations, among other features. Additional symptoms are incoherent speech and behavior ...

mental illness A mental disorder, also referred to as a mental illness or psychiatric disorder, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. Such features may be persistent, relapsing and remitt ...

es such as

schizophrenia Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social wi ...

, again only if inherited from the father's side. As well, ''LRRTM1'' has been associated with measures of schizotypy in non-clinical populations, indicating that the gene may have shared effects on neurodevelopment in both healthy and unhealthy individuals and individuals with schizophrenia. ''LRRTM1'' is also critically involved in synapse formation within the dorsal

lateral geniculate nucleus In neuroanatomy, the lateral geniculate nucleus (LGN; also called the lateral geniculate body or lateral geniculate complex) is a structure in the thalamus and a key component of the mammalian visual pathway. It is a small, ovoid, ventral proj ...

(dLGN) of mice. ''LRRTM1'' aids in the assembly of complex retinogenciulate synapses in mice, which are believed to help process complex visual signals. Lack of this gene shows decreased performance in complex visual tasks.

Clinical significance

See also

References

Further reading