A curriculum outlines what subjects should be studied at what age or grade, and in how much depth. This tool is necessary in a classroom full of children, but not when one learns at home. The gifted kids I know learn "outside the box," light years ahead of their peers in some areas, and totally disinterested in other areas. After the basics are covered (and this is often at a young age for gifted students), wise parents pick and choose their child's learning materials from a wide variety of resources.
One young gifted boy I know was well into high-school math (which he often calculated in his head!) at eight years old, but he showed no interest in reading. His parents and siblings continued to read to him, and he listened to books on tape, but they put no pressure on him to learn to read. Within a year or two he had a need to read for a project he was doing and he learned quickly. In fact, he moved right into the young adult reading level, as his siblings had done before him. His parents understood the need to nurture his individual talents and to support those areas he wasn't quite ready to explore. No prepackaged curriculum provides this opportunity.
Of course, this approach will require more reading and research on your part. However, it is amazing to watch these special kids soar as they explore the world at their own pace, free of preconceived ideas of what they should or could be doing. Gifted Education Comes Home : A Case for Self-Directed Homeschooling by Lisa Rivero explores this learning philosophy for gifted students. I also recommend Rebecca Rupp's incredible book, The Complete Home Learning Source Book. You'll find almost 900 pages of resources on just about every subject imaginable.
Be sure to visit our How to Homeschool area for more homeschool help.