To see, or not to see: In the eye of Retinol and STRA6 signaling

Abstract

Eye morphogenesis proceeds very early during embryogenesis and complete anophthalmia is often associated with major brain anomalies. Here we report a striking pair of human siblings with no eyes and no other clinical manifestations. Genetic mapping revealed a single amino-acid in frame deletion in the STRA6 gene which encodes the Retinol/Vitamin A transporter. Unlike other reported STRA6 mutations which cause the embryonic lethal Matthew-Wood Syndrome, this allele is ocular specific and viable. Disease modeling in Xenopus embryos and in vitro experiments carried out with patient's induced pluripotent stem cells suggests that STRA6 may have alternative functions beyond its ability to transport retinol.