Synaptophysin (SYP) is an integral membrane protein of small synaptic vesicles in brain and endocrine cells. Ozcelik et al.(1990) concluded that the gene has 7 exons distributed over about 20 kb. The SYP locus mapped to Xp11.23-p11.22. Regionalization of the gene on the X chromosome was also done with hamster/human hybrid cells in which various portions of the human X chromosome were present.
