In addition to neonatal diabetes, hypothyroidism, cholestasis and kidney cysts, the boy presented congenital hyporegenerative anemia (Figure 1; Hb at day one: 11.8 g/dl, Hb minimum around day 34: 6.5 g/dl), which has not been reported in individuals with homozygous GLIS3 mutations to date. Here, GSTM1 is linked to cholestasis.