What does the 5 HTT gene do?

The 5-HTT gene has been associated with both depression and autism. The serotonin transporter protein (5-HTT/SLC6A4) transports the neurotransmitter serotonin from synapses to presynaptic neurons. It seems to be an important component in the physiological response to cocaine and amphetamines.

What are the different alleles of 5-HTTLPR?

5-HTTLPR polymorphism was found to have allele frequencies of S, n = 163 (71.5%); LA, n = 24 (10.5%); and LG, n = 41 (18%), and a genotype distribution of S/S, n = 62 (54.4%); S/LG, n = 23 (20.2%); LG/LG, n = 6 (5.3%); S/LA, n = 16 (14%); LG/LA, n = 6 (5.2%); and LA/LA, n = 1 (0.9%).

What does 5-HTTLPR stand for?

5-HTTLPR (serotonin-transporter-linked promoter region) is a degenerate repeat polymorphic region in SLC6A4, the gene that codes for the serotonin transporter. Since the polymorphism was identified in the middle of the 1990s, it has been extensively investigated, e.g., in connection with neuropsychiatric disorders.

What does the serotonin transporter gene do?

Function. The serotonin transporter removes serotonin from the synaptic cleft back into the synaptic boutons. Thus, it terminates the effects of serotonin and simultaneously enables its reuse by the presynaptic neuron.

What is polymorphic variation?

polymorphism, in biology, a discontinuous genetic variation resulting in the occurrence of several different forms or types of individuals among the members of a single species. A discontinuous genetic variation divides the individuals of a population into two or more sharply distinct forms.

What is a short allele?

Functionally, the short allele is associated with reduced transcriptional activity of the serotonin transporter (often termed ‘low-activity’) compared to the long allele (Lesch et al., 1996).

What has been found for individuals who inherit two short alleles of the 5-HTTLPR gene?

All humans inherit a copy of this gene variant from each parent. Study participants with two short 5-HTTLPR alleles were found to be most unhappy in their marriages when there was a lot of negative emotion, such as anger and contempt, and most happy when there was positive emotion, such as humor and affection.

What is serotonin hormone?

Serotonin is a neurotransmitter, and some also consider it a hormone. The body uses it to send messages between nerve cells. It appears to play a role in mood, emotions, appetite, and digestion. As the precursor for melatonin, it helps regulate sleep-wake cycles and the body clock.

Where is serotonin produced?

brain
In the central nervous system (CNS), serotonin is almost exclusively produced in neurons originating in the raphe nuclei located in the midline of the brainstem. These serotonin-producing neurons form the largest and most complex efferent system in the human brain.

What is a polymorphic zone?

A gene is said to be polymorphic if more than one allele occupies that gene’s locus within a population. Gene polymorphisms can occur in any region of the genome. The majority of polymorphisms are silent, meaning they do not alter the function or expression of a gene.

Which serotonin transporter gene makes a person more susceptible to depression?

Gene-by-environment interactions: Negative life events only lead to depression in individuals with a specific genetic set-up that makes them risk-prone to develop depression. The gene most commonly associated with depression is the serotonin transporter gene SLC6A4 (Bleys et al., 2018).

Is low serotonin genetic?

What Causes Serotonin Deficiency? Most cases of serotonin deficiency are idiopathic, meaning doctors are unable to find a specific cause. Some inherited genetic disorders may affect the body’s ability to make or metabolize serotonin.

Is the serotonin transporter gene (5-HTT) involved in psychiatric disorders?

The serotonin transporter gene (5-HTT) variant and psychiatric disorders: review of current literature Both serotonin and the serotonin transporter, which transports the neurotransmitter serotonin from synaptic spaces into presynaptic neurons, play an important role in the pathophysiology of several psychiatric disorders.

What is the serotonin transporter gene promoter variant?

Mutations associated with the serotonin transporter gene may result in changes in serotonin transporter function. The serotonin transporter gene promoter variant, consisting of a long (L) and a short (S) variant, is one of the major factors which contribute to the etiology of many psychiatric disorders.

What does the repeat length variant of the serotonin gene do?

This repeat length variant in the promoter region of this gene has been shown to affect the rate of serotonin uptake and may play a role in post-traumatic stress disorder and depression-susceptibility in people experiencing emotional trauma.

Is 5-HTTLPR mutation associated with IBS-constipation predominant type in East Asian population?

For SLC6A4, we found a new SNP that showed a lower P-value than in the GAIN-MDD GWAS This metaanalysis shows a positive association between the L allele and LL genotype of 5-HTTLPR mutation and IBS-constipation predominant type in the East Asian population but not in the Caucasian population.