Heterozygosity for a single mutation in the ABCC6 gene may closely mimic PXE: consequences of this phenotype overlap for the definition of PXE.

Objectives: To illustrate a phenotypic overlap consisting of usual, but limited, or atypical manifestations of pseudoxanthoma elasticum (PXE) between heterozygous carriers of a single ABCC6 mutation and patients diagnosed with PXE, carriers of homozygous or compound heterozygous mutations.

Design: Evaluation for full and typical, incomplete, mild, or overlooked PXE during a 5-year period (2001-2005) based on the following 1992 expert consensus conference items: (1) yellowish papular skin eruption, (2) dermal elastorrhexis and mineralization of elastic fibers in lesional skin, and (3) angioid streaks. Testing for ABCC6 mutations was performed in all cases after informed consent.

Osteoid osteoma multifocally located and recurrent in the carpus.

The authors report a case of osteoid osteoma located simultaneously at the right carpitate and at the proximal part of the right third metacarpian. A 31-year-old man presented in 1997 an osteoid osteoma involving the right capitate. One year after the surgical excision of the tumor, a second osteoid osteoma reappears to the same place requiring a 2nd intervention.