RESUMEN
<p><b>OBJECTIVE</b>To explore the clinical features and mutations of MYO5B gene in a family affected with microvillus inclusion disease.</p><p><b>METHODS</b>Clinical data of an infant affected with microvillus inclusion disease was collected. Genomic DNA was extracted from peripheral blood samples from the patient and her parents. PCR amplification and Sanger sequencing were performed to analyze all the exons and their flanking sequences of the MYO5B gene.</p><p><b>RESULTS</b>The patient presented with complicated manifestations including respiratory distress syndrome, dehydration, acidosis, bowel dilatation, liver and kidney dysfunction, and severe and intractable diarrhea. A compound mutation of the MYO5B gene, i.e., IVS37-1G>C/c.2729_2731delC (p.R911Afs916X), was discovered in the patient. The former was a splice-site mutation inherited from the mother, while the latter was a frameshift mutation inherited from the father. Both were not reported previously.</p><p><b>CONCLUSION</b>Based on the clinical and molecular evidence, the patient was diagnosed with microvillus inclusion disease. Above finding has expanded the mutation spectrum of the MYO5B gene, which can provide valuable information for genetic counseling for the family.</p>