Hb Montreal II: a novel elongated beta-globin variant caused by a frameshift mutation [beta142 (-C)].

We report a novel elongated C-terminal beta hemoglobin (Hb) variant caused by a single nucleotide (C) deletion at codon 143 (nucleotide 480 of GenBank entry NM_000518). This deletion leads to the substitution of histidine 143 by threonine, and displaces the beta Hb gene stop codon from codon 147 to codon 157. It was identified in a 30-year-old man from Montreal, and called Hb Montreal II.