Hemoglobin Dhonburi alpha 2 beta 2 126 (H4) Val----Gly: a new unstable beta variant producing a beta-thalassemia intermedia phenotype in association with beta zero-thalassemia. 
While investigating the mechanism of a beta-thalassemia intermedia phenotype in a 34 year old Thai male, a new Hb variant beta 126 Val----Gly named Hb Dhonburi was discovered.  Genetic and structural studies revealed the existence of a beta zero-thalassemia genotype in association with the beta variant.  The new variant is unstable but exhibits normal oxygen binding properties.  Hb Dhonburi was also discovered in the mother of the propositus in association with Hb E.