Abstract
Purpose: :
To check histopathological and phenotypical variability in expression in adult homozygous and heterozygous persons having the c.3775delT mutation in the ABBC6 gene.
Methods: :
Participants from one genetic isolate. Standardized questionnaire, dermatological and ophthalmologic examination. Skin biopsies from affected skin, a predilection site and/or a scar were examined and compared with biopsies from control persons in a masked way by two experienced dermatopathologists.
Results: :
There was a high phenotypic variability among the 15 homozygous participants. Skin signs could vary from severe at age 30 to no signs at age 57 years. Histopathology differed from no abnormalities to marked elastin fragmentation and clumping with calcium deposits. Visual acuity was (sub)normal under the age of 50 years and varied from subnormal to legal blindness around age 60. Five cases (33%) had symptomatic cardiovascular disease. None of the 44 heterozygous participants had any sign of PXE on dermatologic, histopathologic and/or ophthalmologic examination, but 32% had cardiovascular disease.
Conclusions: :
Persons homozygous for the ABCC6 c.3775delT PXE mutation have a highly variable phenotype, with no marked correlation between severity of skin, eye or cardiovascular abnormalities. Heterozygous participants did not demonstrate any PXE signs or symptoms.