The MPP7 gene encodes an enzyme belonging to the p55 stardust subset of the Membrane-Associated Guanylate Kinase (MAGUK) family. Members of the MAGUK family function as adaptor proteins that help in the assembly of protein complexes at locations of cell-cell contact. They are thus involved in the formation of synapses, adherens junctions and tight junctions. MPP7 specifically functions by forming a complex with DLG1, a polarity protein, facilitating the establishment of epithelial cell polarity and bicellular tight junction assembly.
The MPP7 gene, located on the short arm of chromosome 10, spans a length of 283.4 kb of DNA. Its coding sequence is spread across 22 exons and it encodes a 65.5 kDa protein product composed of 576 amino acids. An additional 42 kDa isoform of the MPP7 protein exists due to an alternatively spliced transcript variant. While the gene is widely expressed in the human body, overexpression is seen in the retina and placenta.
Monies et al. (2017) analyzed the genomic landscape of Saudi Arabia based on the findings of 1000 diagnostic panels and exomes. One patient, a 12-year-old male with ataxia, was subjected to whole exome sequencing. This helped identify a homozygous mutation (c.1251C>G, p.Y417X) in exon 16 of the patient’s MPP7 gene. This gene mutation was considered a candidate for pathogenicity as it was a novel variant located within the autozygome and was predicted to be deleterious; and as the MAGUK protein family (to which MPP7 belongs) has been implicated in synapse formation. The authors noted the need for independent confirmation of this association.
To contribute with your findings to the content of this record, please fill the CTGA Database Information Submission Form and email it, along with supportive documents, to firstname.lastname@example.org.