Disclosed is an electrical connector assembly which comprises an insulative body, a PCB and a base. In one aspect, the invention provides isolated polynucleotides that encode SYNGAP or fragments or derivatives thereof. A power amplifier module of the present invention comprises the multi-layer circuit board, a semiconductor amplifier fabricated in the multi-layer circuit board, and an impedance matching circuit coupled to the output of the semiconductor amplifier. Since the lower rail is not divided, the linearity is ensured and the moving plate does not stutter so that transfer of the substrate at high speed can be performed.