Search parameter by reference sequence and variant coordinate. This will refer to part of a locus or part of a gene where search region will be represented in 1-based system. Since the coordinateSystem can either be 0-based or 1-based, this search query will include the result of both coordinateSystem that contains the equivalent segment of the gene or whole genome sequence. For example, a search for sequence can be represented as referenceSeqId-variant-coordinate=NC_000001.11$lt345$gt123, this means it will search for the MolecularSequence resource with variants on NC_000001.11 and with position >123 and <345, where in 1-based system resource, all strings within region NC_000001.11:124-344 will be revealed, while in 0-based system resource, all strings within region NC_000001.11:123-344 will be revealed. You may want to check detail about 0-based v.s. 1-based above.