To date, approximately 200 families have been reported with pathogenic FLCN mutations (Schmidt et al., 2005; Graham et al., 2005; Toro et al., 2008; Misago et al., 2008; Frohlich et al., 2008; Leter et al., 2008; Woodward et al., 2008; Kunogi et al., 2010). However, BHD syndrome is believed to be under-diagnosed; partly because it is so rare that doctors are often unfamiliar with it, and partly because its phenotypic variation can make it difficult to identify (Menko et al., 2009). Further epidemiological research, to identify more patients with BHD and to identify novel mutations, would help ascertain the true prevalence of BHD syndrome. This research may also help to identify a genotype-phenotype correlation, which could lead to potential personalised treatments for BHD syndrome and an accurate prediction of future symptoms.
