Hb Niigata [beta1(NA1)Val-->Leu] in a Romanian individual resulting from another nucleotide substitution than that found in the Japanese.

We present a new case of Hb Niigata that we named Hb Niigata(C), observed in a woman from Romania, with a mutation different from that described in Japanese (GTG-->CTG instead of GTG-->TTG). This single nucleotide substitution replaces the valine residue for leucine at codon 1 and causes retention of the N-terminal methionine leading to an elongated beta chain. This mutation was without any hematological consequences.