We found that all of the patients diagnosed with SMN1-related spinal muscular atrophy-1 (OMIM 253300), very long-chain acyl-CoA dehydrogenase deficiency (OMIM 201475), microvillus inclusion disease (OMIM 251850), or SCNN1A-related Pseudohypoaldosteronism type I (OMIM 264350) died with each of these conditions being detected in at least two of the study cohort infants. This evidence concerns the gene SMN1 and microvillus inclusion disease.