This gene encodes a member of the frizzled-related protein family. The encoded protein plays an important role in eye development and mutations in this gene have been associated with nanophthalmos, posterior microphthalmia, retinitis pigmentosa, foveoschisis, and optic disc drusen. The protein is encoded by a bicistronic transcript which also encodes C1q and tumor necrosis factor related protein 5 (C1QTNF5). [provided by RefSeq, Jun 2013]

The MFRP gene, located on the long arm of chromosome 11, is about 7.7 kb in length.  Its coding sequence is made up of 15 exons.  The C1QTNF5 gene (C1q- and Tumor Necrosis Factor-Related Protein 5), a retina-specific collagen gene, is located within the 3’ untranslated region of exon 13 of MFRP and hence both genes are expressed as a bicistronic transcript.  Levels of expression are highest in the Retinal Pigment Epithelium and the ciliary body. 

The protein encoded by the gene is made up of 579 amino acids and is approximately 62 kDa in size.  Based on the amino acid sequence, the protein has been shown to contain regions with similarities to the cysteine-rich domain (CRD) of frizzled protein and the CUB domain found in proteins such as complement subcomponent C1r/C1s, Uegf and bone morphogenetic protein-1.  More than a dozen mutations, both homozygous and compound heterozygous, have been linked to microphthalmia, isolated 5 and nanophthalmos 2.