Anterior segment dysgenesis associated with Williams-Beuren syndrome: a case report and review of the literature

Abstract

Background: Williams-Beuren syndrome is characterized by mild mental retardation, specific neurocognitive profile, hypercalcemia during infancy, distinctive facial features and cardiovascular diseases. We report on complete ophthalmologic, sonographic and genetic evaluation of a girl with a clinical phenotype of Williams-Beuren syndrome, associated with unilateral anterior segment dysgenesis and bilateral cleft of the soft and hard palate. These phenotypic features have not been linked to the haploinsufficiency of genes involved in the microdeletion.

Case presentation: A term born girl presented at the initial examination with clouding of the right cornea. On ultrasound biomicroscopy the anterior chamber structures were difficult to differentiate, showing severe adhesions from the opacified cornea to the iris with a kerato-irido-lenticular contact to the remnant lens, a finding consistent with Peters' anomaly. Genetic analyses including FISH confirmed a loss of the critical region 7q11.23, usually associated with the typical Williams-Beuren syndrome. Microsatellite analysis showed a loss of about 2.36 Mb.

Conclusions: A diagnosis of Williams-Beuren syndrome was made based on the microdeletion of 7q11.23. The unique features, including unilateral microphthalmia and anterior segment dysgenesis, were unlikely to be caused by the microdeletion. Arguments in favor of the latter are unilateral manifestation, as well as the fact that numerous patients with deletions of comparable or microscopically visible size have not shown similar manifestations.

Figure 1

Anterior segment photograph, left eye. Figure 1 depicts an anterior segment photograph, presenting a central clouding and vascularized microcornea of the right eye; no pathological findings of the left eye were recorded.

Figure 2

Present an ultrasound biomicroscopy image (UBM) of both eyes taken with 50 MHz transducer (P60TM, Paradigm Medical Industries, Inc. Salt Lake City, UT). A depicts the ultrasound biomicroscopy findings of the right eye: the transverse section in primary position shows irregularity of the corneal-depth with paracentral crater-like depression (arrow, ↑) involving the corneal endothelium and the Descemet’s membrane. The anterior chamber structures are hardly distinguishable (asterisk, *) showing kerato-irido-lenticular contact (open arrowheads, >). B shows the ultrasound biomicroscopy of the left eye, representing a normal, structured anterior segment.