Abstract
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 β chain. This mutation was without any hematological consequences.