Many thanks for checking and investigating. It is a shame there's nothing more recent. From p23 of Curatolo(2003), "Diagnosic Criteria", I get:
The rate of occurrence of tuberous sclerosis at birth is unknown...(paragraph continues with stats trying to come up with a figure)... This indicates that the real incidence at birth may be as high as 1:6000 (Webb et al. 1993, Cardiac rhabdomyomas and their association with tuberous sclerosis, Arch Dis Child 68:367–70)

Earlier, when talking about Hunt and Lindenbaum's 1984 study, he says "The scientists believed that the birth prevalence might be even higher than it is now considered to be." I don't have that paper so don't have more details.

An editorial by Fryer (Journal of the Royal Society of Medicine 1991, 84:699) says "... suggesting a birth incidence of 1:10000". I don't have the Osborne paper you mention. I've seen 1:5800 mentioned but don't know its source at present.

My sources seem to use incidence and prevalence interchangeably wrt to birth. I'm happy to change it if you think it may be less ambiguous.

The list of prevalence figures throughout the years comes from Curatolo (2003), Table 2.6, page 22. This in turn is based on an earlier table by Shepherd in his short chapter "The Epidemiology of Tuberous Sclerosis Complex" in the book Gomez 1999. The earlier table doesn't have the O'Callaghan figure.

I'll see if I can get hold of some of the other papers, but it isn't easy. °Talk