Atypical angioid streaks in a patient with a monoallelic ABCC6 mutation

Pseudoxanthoma elasticum (PXE) is characterized by aberrant calcification of elastic tissues throughout the body causing varying degrees of skin, cardiac, and ocular disease. Although PXE is classically regarded as an autosomal recessive disease, recent reports have demonstrated a haploinsufficiency phenotype, in which carriers of monoallelic ATP-binding cassette transporter (ABCC6) gene mutations demonstrate mild manifestations of PXE. In this case report, we describe a patient with a monoallelic ABCC6 mutation and atypical angioid streaks.

Case report.

A 31-year-old male with a history of paroxysmal tachycardia and right ventricular enlargement presented to the Eye Emergency Department complaining of bilateral eye pain with occasional flashes and bitemporal headaches. Family history was notable for unspecified heart disease in his father but no ocular disease. Best-corrected visual acuity was 20/20 in both eyes. Posterior segment examination demonstrated linear hypopigmented lesions radiating from the superior arcades of both eyes. Fundus autofluorescence of the lesions demonstrated speckled hypo- and hyperautofluorescence and fluorescein angiography revealed window defects consistent with atypical angioid streaks. Genetic testing was positive for a heterozygous c.2889C>A (p.Cys963*) mutation in the ABCC6 gene.

The current case demonstrates the potential for PXE carriers to display both systemic and ophthalmic manifestations of the disease. Individuals with known or suspected monoallelic ABCC6 mutations may benefit from genetic counseling and regular examination.