Dominantly inherited beta thalassaemia intermedia caused by a new single nucleotide deletion in exon 2 of the beta globin gene: Hb morgantown (beta91 CTG>CG).

Family members in multiple generations of an Irish-American family were investigated for moderate to severe microcytic anaemia, inherited in an autosomal dominant fashion. A novel frameshift mutation of the beta globin gene was discovered. This study highlights the importance of considering dominantly inherited beta thalassemia in the investigation of anaemia, even in patients with ethnic backgrounds not usually associated with beta thalassaemia.