A case report of PHF6 mosaicism: Beyond the classic Börjeson-Forssman-Lehmann syndrome.

We report a 6-year-old female with linear skin hyperpigmentation on the axillae and groin, intellectual disability, dysplastic teeth and nails, and facial dysmorphism who was diagnosed with a novel PHF6 pathogenic splicing variant. Males with PHF6 mutations have been associated with the X-linked recessive disorder Borjeson-Forssman-Lehmann, but females have a distinct phenotype which is likely modulated by X-inactivation.