In addition to the SQL reference that Dan links to, make sure to read SearchCursor—Data Access module | Documentation.
In order to use SQL SELECT criteria, like DISTINCT, with ArcPy DA cursors, you will need to use a sql_clause argument to define what Esri calls a "SQL prefix." In general, and particularly with file geodatabases, SQL SELECT criteria do not work with spatial data types. For example you cannot write something like, SELECT DISTINCT shape. If you want to compare spatial data, you will need to create another column(s) and put a spatial property in it, e.g., create a WKT field.
Assuming your four fields are text (pnt being some text-based property or representation of your point data), your where clause would be:
where_clause = "NOT(name IS NULL OR corridor IS NULL OR pnt IS NULL OR zone IS NULL)"
and your SQL clause would be:
sql_clause = ("DISTINCT", None)
and your cursor definition would look like:
arcpy.da.SearchCursor(gdbConnectTable, ["name", "corridor", "pnt", "zone"], where_clause=where_clause, sql_clause=sql_clause)