Inherited macrocephaly-hamartoma syndromes.

Recent discoveries in the molecular biology of the phosphatase and tensin homolog (PTEN) locus in the q22-23 region of chromosome 10 prove and/or suggest that several syndromes previously considered to be clinically and genetically distinct entities should actually be unified into a single entity. This conclusion is most secure for the Cowden and "Bannayan-Zonana" phenotypes, but almost certainly should also include the "Riley-Ruvalcaba" and Lhermitte-Duclos phenotypes as well benign familial macrocephaly and external hydrocephalus. The clinical and molecular data supporting this unification are presented along with a proposal for new nomenclature-the PTEN MATCHS (macrocephaly, autosomal dominant, thyroid disease, cancer, hamartomata, skin abnormalities) syndrome-based on the observed clinical abnormalities.