Macrodactyly in tuberous sclerosis complex: Case report and review of the literature

Macrodactyly in the context of tuberous sclerosis complex (TSC) is a known but rare manifestation. We report the case of a boy diagnosed with TSC at 2 years and 4 months of age, presenting with bilateral macrodactyly of the first three fingers of both hands, with underlying radiographic changes, in whom molecular analysis identified a frameshift mutation on the TSC1 gene (encoding hamartin), leading to a premature stop codon. We reviewed the literature for reported cases of TSC patients with the same manifestation. In four of 14 patients, including ours, macrodactyly caused some type of joint limitation or flexion deformity, thus contradicting the established idea that this is a finding without clinical significance. Our patient is, to our knowledge, the first reported to have clear bilateral involvement. We briefly discuss the underlying mechanism for this phenomenon, which has yet to be fully elucidated, although somatic mosaicism for loss of heterozygosity at TSC loci is a plausible explanation. © 2016 Wiley Periodicals, Inc.