preferred_name: an alpha-D-glucuronosyl-(1<->6)-1D-myo-inositol-1-phospho-N-[(R)-2-hydroxy-very-long-chain fatty acyl]-(R)-4-hydroxysphingoid base + UDP + H(+) => a 1D-myo-inositol-1-phospho-N-[(R)-2-hydroxy-very-long-chain fatty acyl]-(R)-4-hydroxysphingoid base + UDP-alpha-D-glucuronate