The phenotypic overlap between patients with p.S1344L mutation and GLOW syndrome provide clinical support for recent discoveries that RNase IIIa-Ser1344 site mutations impede miRNA-5p biogenesis analogous to DICER1 hotspot mutations in the RNase IIIb domain. The gene discussed is DICER1; the disease is global developmental delay - lung cysts - overgrowth - Wilms tumor syndrome.