Twin A Twin B Controls (range) VLCFAs       C24:C22 2.209 2.620 0.0545-0.941 C26:0 (µmol/L) 7.010 5.880 0.269-0.923 C26:1 (µmol/L) 9.630 7.780 0.247-1.095 C26:C22 0.701 0.736 0.005-0.017 Phytanic acid (µmol/L) 1.2 1.2 <10

Table 1: Serum Levels of very long chain Fatty acids (VLCFA) and phytanic acid in both twins, on day one of life.