Hi Claudine
Does the mother realise that if she does leave all her assets to her child outright rather than in a discretionary trust (I am not really familiar with Vulnerable persons trusts, they have always looked to be more bother than they are worth on the rare occasion I have looked although things may have changed), then he may well lose some if not all of his entitlement to benefits that he would otherwise keep.
At the moment, receipts from a discretionary trust do not count in assessing means tested benefits. The loss in benefits would quite possibly outweigh the costs of running a trust. Has she also considered that as someone with learning disabilities he is at an increased risk of being taken advantage of by the unscrupulous when he comes into his inheritance and it may soon disappear.
Good luck.
Sara Spencer
Trust and Estate