Binary logistic regression was used to compare the number of eight key features identified (absent corpus callosum, cataracts, hypopigmentation, cardiomyopathy, immune dysfunction, profound developmental delay, progressive microcephaly, failure to thrive), with the likelihood of a positive EPG5 genetic test in all 66 patients tested (36 EPG5-positive, 30 EPG5-negative), indicating that the presence of all eight features had a specificity of 97%, and a sensitivity of 89% for a positive EPG5 genetic test. This evidence concerns the gene EPG5 and Failure to thrive.