Basaloid Follicular Hamartoma Syndrome
- Basaloid follicular hamartoma syndrome can be an autosomal dominant disorder like BHD, or it can arise spontaneously.
- It is linked to a mutation in the PTCH gene. Mutations in this gene are also associated with nevoid basal cell carcinoma syndrome, and as such it is important to closely monitor this condition in case cancer develops (1). A biopsy can distinguish whether a lesion is benign or malignant.
- Basaloid follicular hamartoma syndrome is characterised by small skin-coloured or brown lesions called basaloid follicular hamartomas most commonly found on the face, neck and trunk.
Brooke-Spiegler Syndrome (BSS)
- Brooke-Spiegler syndrome is an autosomal dominant syndrome caused by mutations in the CYLD gene.
- BSS is characterised by multiple skin appendage tumours such as cylindroma, trichoepithelioma, and spiradenoma which typically appear on the head and neck.
- Cowden syndrome is an autosomal dominant syndrome. The majority of cases are caused by mutations in the PTEN gene, however mutations in KLLN, WWP1, SDHB, SDHC, SDHD, PI3KCA or AKT1 have also been identified.
- Cowden syndrome is associated with a higher risk of developing several types of cancer. Skin lesions associated with this syndrome are skin tags and lesions in the oral mucosa.
Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC)
- HLRCC is an autosomal dominant syndrome caused by mutations in the FH gene.
- HLRCC is characterised by the development of benign skin bumps (called piloleiomyomas) in both men and women during their twenties. Women also often develop large uterine fibroids from the same age.
- HLRCC is associated with an increased risk of developing kidney cancer and as such regular screening is important to detect any tumours as early as possible.
- You can learn more about HLRCC at the HLRCC Family Alliance website.
- Rombo syndrome is an autosomal dominant genetic disease, although the gene is not known. The syndrome has only been identified in one family.
- Related skin lesions: Milia and Telangiectasia.
Familial multiple discoid fibromas (FMDF)
- FMDF is an autosomal dominant genetic disease.
- FMDF is similar to BHD syndrome but patients only have skin lesions, similar to those found in BHD syndrome. Kidney or lung symptoms seen in BHD syndrome have not been reported in FMDF.
- FMDF is caused by mutations in the FNIP1 gene, which interacts with the BHD gene, FLCN.
- You can learn more about FMDF on the BHD Research Blog.
Tuberous Sclerosis Complex (TSC)
- TSC is an autosomal dominant genetic disorder caused by mutations in the TSC1 or TSC2 genes.
- TSC is characterised by the development of non-cancerous growths in multiple organs. Skin lesions are very common in people affected by TSC, particularly facial angiofibromas (reddish-pink overgrowths of skin).
- You can learn more about TSC at the UK) or TS Alliance (USA) websites.
1. Gumaste P, Ortiz AE, Patel A, Baron J, Harris R, Barr R. Generalized basaloid follicular hamartoma syndrome: A case report and review of the literature. In: American Journal of Dermatopathology [Internet]. Lippincott Williams and Wilkins; 2015 [cited 2021 May 18]. p. e37–40. Available from: https://journals.lww.com/amjdermatopathology/Fulltext/2015/03000/Generalized_Basaloid_Follicular_Hamartoma.17.aspx
Last Updated: May 2021
Review date: May 2024