SLC12A3 and Gerstmann syndrome: The combined uEV levels of these proteins, together with the abundance of NCC and NKCC2 proteins, whose specific deficiency is the hallmark of GS and BS1, seem to discriminate among the four syndromes, and, in particular, between the two pairs of syndromes (GS/BS3, and BS1/BS2), which may present with overlapping clinical phenotypes.