Ultrasound diagnosis of bilateral cataracts in a fetus with possible cerebro-ocular congential muscular dystrophy during the routine second trimester anomaly scan

Prenatal presentation of Walker–Warburg syndrome with a POMT2 mutation: an extended fetal phenotype

Background

Walker–Warburg syndrome (WWS) is a rare, lethal, genetically, and clinically heterogeneous congenital muscular dystrophy resulting from defective glycosylation of α-dystroglycan (α-DG) and is associated with both cranial and ocular malformations. Prenatal detection of posterior fossa anomalies in association with hydrocephalus are nonspecific, however, an additional finding of eye anomalies are typical for WWS. The purpose of this report is to elucidate the pattern of associated malformations in a fetus with WWS born to 3rd degree consanguineously married couple. Additionally, the fetal ultrasonography revealed congenital heart disease, clenched hands, and talipes equinovarus; these findings have not been previously reported and represent an expansion of prenatal spectrum associated with WWS.

Case presentation

We report on a specific sonographic pattern of congenital anomalies including hydrocephalus, agenesis of corpus callosum, and Dandy–Walker malformation. Ocular abnormalities include microphthalmia, cataract, and an echoic structure suggestive of persistent primary vitreous. Other features include congenital heart disease, unilateral multicystic kidney, and previously unreported findings of bilateral clenched hands and talipes equinovarus. The molecular analysis detected a homozygous splicing mutation, c.924-2A>C, in the POMT2 gene; this variant segregated with the phenotype.

Conclusion

WWS syndrome has characteristic prenatal ultrasound findings which can improve the prenatal identification of this condition and help in guiding the molecular diagnosis and counseling. The detection of bilateral clenched hands and talipes equinovarus is a novel finding that further expands the phenotypic spectrum of WWS.

Recent developments in the management of congenital cataract

Congenital cataract is a rare eye disease, one of the leading treatable causes of low vision in children worldwide. Hereditary cataracts can be divided in syndromic and non-syndromic cataracts. Early diagnosis in congenital cataracts is key to reach good visual function. Current surgical techniques, that combine microincision cataract extraction and primary intraocular lens (IOL) implantation, have improved childhood cataract outcome. Complications include posterior capsule opacification (PCO), aphakic or pseudophakic glaucoma, uveitis, pupil displacement and IOL decentration. A recent study using a modified Delphi approach identified areas of consensus and disagreement in the management of pediatric cataract. A consensus or near consensus was achieved for 79% of the questions, however 21% of the questions remained controversial, as for IOL implantation strategy. Congenital cataracts show a highly variable phenotype and genotype, and can be related to different mutations, genetic variance, and other risk factors. Congenital cataracts can be associated with other ocular developmental abnormalities, including microphthalmia, microcornea, or aniridia and with systemic findings. Next-generation sequencing (NGS) and forthcoming new ultra-high-throughput sequencing represent excellent tools to investigate the genetic causes of congenital cataracts. A better recognition of different clinical presentations and underlying etiologies of congenital cataracts may lead to the development of new approaches to improve visual outcome after cataract surgery and promote early detection of systemic associated syndromes.