The Abelson helper integration site 1 (AHI1) is a protein coding

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

that is known for the critical role it plays in

brain development The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head ( cephalization), usually near organs for special sens ...

. Proper cerebellar and cortical development in the

human brain The human brain is the central organ (anatomy), organ of the nervous system, and with the spinal cord, comprises the central nervous system. It consists of the cerebrum, the brainstem and the cerebellum. The brain controls most of the activi ...

depends heavily on AHI1. The AHI1 gene is prominently expressed in the embryonic

hindbrain The hindbrain, rhombencephalon (shaped like a rhombus) is a developmental categorization of portions of the central nervous system in vertebrates. It includes the medulla, pons, and cerebellum. Together they support vital bodily processes. Met ...

and

forebrain In the anatomy of the brain of vertebrates, the forebrain or prosencephalon is the rostral (forward-most) portion of the brain. The forebrain controls body temperature, reproductive functions, eating, sleeping, and the display of emotions. Ve ...

. AHI1 specifically encodes the Jouberin protein and mutations in the expression of the gene is known to cause specific forms of

Joubert syndrome Joubert syndrome is a rare autosomal recessive genetic disorder that affects the cerebellum, an area of the Human brain, brain that controls balance and coordination. Joubert syndrome is one of the many genetic syndromes associated with syndromic ...

. Joubert syndrome is autosomal recessive and is characterized by the brain malformations and

mental retardation Intellectual disability (ID), also known as general learning disability (in the United Kingdom), and formerly mental retardation (in the United States), Rosa's Law, Pub. L. 111-256124 Stat. 2643(2010).Archive is a generalized neurodevelopmental ...

that AHI1 mutations have the potential to induce. AHI1 has also been associated with

schizophrenia Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...

and

autism Autism, also known as autism spectrum disorder (ASD), is a neurodevelopmental disorder characterized by differences or difficulties in social communication and interaction, a preference for predictability and routine, sensory processing d ...

due to the role it plays in brain development. An AHI1 heterozygous knockout mouse model was studied by Bernard Lerer and his group at

Hadassah Medical Center Hadassah Medical Center () is an Israeli medical organization established in 1934 that operates two university hospitals in Jerusalem (one in Ein Karem and one in Mount Scopus) as well as schools of medicine, dentistry, nursing, and pharmacology ...

Jerusalem Jerusalem is a city in the Southern Levant, on a plateau in the Judaean Mountains between the Mediterranean Sea, Mediterranean and the Dead Sea. It is one of the List of oldest continuously inhabited cities, oldest cities in the world, and ...

to elucidate the correlation between alterations in AHI1 expression and the pathogenesis of

neuropsychiatric Neuropsychiatry is a branch of medicine that deals with psychiatry as it relates to neurology, in an effort to understand and attribute behavior to the interaction of neurobiology and social psychology factors. Within neuropsychiatry, the mind i ...

disorders. The core temperatures and

corticosterone Corticosterone, also known as 17-deoxycortisol and 11β,21-dihydroxyprogesterone, is a 21-carbon steroid hormone of the corticosteroid type produced in the cortex of the adrenal glands. In the very rare case of congenital adrenal hyperplasia due ...

secretions of the heterozygous knockout mice after exposure to environmental and visceral stress exhibited extreme repression of

autonomic nervous system The autonomic nervous system (ANS), sometimes called the visceral nervous system and formerly the vegetative nervous system, is a division of the nervous system that operates viscera, internal organs, smooth muscle and glands. The autonomic nervo ...

and hypothalamic-pituitary-adrenal responses. The knockout mice demonstrated an increased resilience to different types of stress and these results lead to a correlation between emotional regulation and neuropsychiatric disorders. Jouberin is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

that in humans is encoded by the ''AHI1''

References

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Further reading