Crucial in the assembly, expression, and functional modulation of the heterotrimeric complex of the sodium channel. The subunit beta-2 causes an increase in the plasma membrane surface area and in its folding into microvilli. Interacts with TNR may play a crucial role in clustering and regulation of activity of sodium channels at nodes of Ranvier (By similarity). The voltage-sensitive sodium channel consists of an ion conducting pore forming alpha-subunit (SCN2A) regulated by one or more beta subunits (SCN1B, SCN2B, SCN3B and SCN4B). SCN1B and SCN3B are non-covalently associated with SCN2A. SCN2B and SCN4B are disulfide-linked to SCN2A. Brain specific. The disease is caused by variants affecting the gene represented in this entry. Genetic variations in SCN2B may be involved in Brugada syndrome (PubMed:23559163). This tachyarrhythmia is characterized by right bundle branch block and ST segment elevation on an electrocardiogram (ECG). It can cause the ventricles to beat so fast that the blood is prevented from circulating efficiently in the body. When this situation occurs, the individual will faint and may die in a few minutes if the heart is not reset. Belongs to the sodium channel auxiliary subunit SCN2B (TC 8.A.17) family.