• Fenotipo
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RELATIONSHIP BETWEEN GENOTYPE AND PHENOTYPE: association between genetic polymorphisms and human capabilities.

Dopamine is an important neurotransmitter of emotional brain, syntetized from tyrosine, an amino acid normally present in the diet and that has to cross the blood brain barrier, thus, be actively concentrated in the dopaminergic neuron. Once produced dopamine can be converted into adrenaline through two other enzymes which provide for processing prior to noradrenaline. In addition to having a large role in the coordination of motor behavior (a deficit of this system is the symptoms of Parkinson's disease), is critical for adaptive behavior and emotional implications. The pleasure and emotional processes are regulated by the dopamine reward like the rewards resulting from eating, drinking, to reproduce the success in the struggle and competition. The euphoria associated with the narrow escape was orchestrated by dopamine.
The purpose of my study was to analyze some polymorphisms, as described below, that cause in the individual the predisposition to attention deficit, which is why I wanted to see whether the same polymorphism could interfere with some simple everyday reactions, such as driving, and this has been possible thanks to the collaboration with the Department of Roads and Transport Engineering Faculty of the University of Pisa, for putting at our disposal a driving simulator, that allowed us to perform phenotypic characterization of human volunteers genotyped for four polymorphisms examined.
Polymorphic variants in several genes involved in the regulation of dopamine and related neurotransmitters appear to be associated with ADHD (ASHERSON Philip et al.). The attention deficit hyperactivity disorder (ADHD) is a very complex childhood behavioral disorder, and the common inheritance characterized by inappropriate levels of hyperactivity, impulsivity and inattention. From these observations arises the interest in dealing with a study of the dopamine receptor 2 (DRD2) with several polymorphisms including the rs6277 C / T (JL Bolton et al.) which seems to be involved in a general decrease in cognitive function. DRD2 is associated with the gene ANKK1, encoding a Ser / Three kinases involved in signal transduction. From association studies, in fact, it was revealed a SNP, TaqlA (rs1800497), the A1 allele appears to be associated with disorders of attention also due to alcohol intake. Another gene has been the object of our attention: COMT, which map on CRH 22 and encodes an enzyme that degrades dopamine and catecholamines, and is important in the signal transduction of monoamines. In a study of Halleland H. et al. (26) has been suggested that symptoms of the disorder of attention are linked to low levels of dopamine in the prefrontal cortex. At the level of this gene was found a Val158Met polymorphism rs6269, which together with other SNPs may be implicated in the lack of cognitive activities of individuals, in particular seems to be associated with ADHD.
The work done in the laboratory has been to genotype fifty volunteers starting from DNA extraction from buccal mouthwash with a 0.9% saline, followed by ASO-PCR and electrophoresis on an agarose gel 2%.