Hb I-Toulouse in association with homozygosity for the α3.7 deletion in a Pacific Island woman


Only four cases of Hb I-Toulouse have been reported to date. Current literature associates Hb I-Toulouse in the heterozygote with a mild chronic hemolytic anemia. The variant is mildly unstable with a tendency to form metHb. The quantity of the variant in heterozygotes has been reported as varying between 33 to 40%. This report confirms the finding from a single case, that a reduced percentage of Hb IToulouse along with microcytosis can be attributed to the co-inheritance of an abnormal α globin genotype. This current case was found in a woman of Pacific People ethnicity residing in New Zealand. There is a high prevalence of α thalassemia in this ethnic group and New Zealand has the highest Pacific population in the world. Therefore, if a reduced percentage of Hb I-Toulouse is found with microcytosis and normal iron studies, co-inheritance with α thalassemia should be considered.


目前仅有四例Hb I-Toulouse的病例报告。 当前的文献将杂合子中的Hb I-Toulouse与慢性溶血性贫血相关联。 这种变异体轻度不稳定,有形成高铁血红蛋白(metHb)的倾向。 杂合子中变异体数量据报道为33%至40%不等。 本报告证实从单一病例得到的结果,即伴有小红细胞症的更低Hb I-Toulouse百分比可被归结为异常α球蛋白基因型的合并遗传。 该例当前病例在一名居住在新西兰的太平洋诸岛族裔女性身上发现。 在这个族群中存在较高的α地中海贫血患病率,而在全世界新西兰的太平洋诸岛族裔人口最多。 因此,如果发现Hb I-Toulouse的百分比更低,同时伴有小红细胞症并且检查铁含量正常,则应考虑α地中海贫血的合并遗传。



PlumX Metrics


Download data is not yet available.

Author Biography

Beverley Pullon, Hematology Department, Waikato Hospital

Haematology Scientist

Charge of Haemolytics Department

Waikato Hospital

Case Reports
I-Toulouse, alpha thalassemia, homozygosity-α3.7, Pacific People, New Zealand.
  • Abstract views: 1001

  • PDF: 349
  • HTML: 401
How to Cite
Pullon, B. (2016). Hb I-Toulouse in association with homozygosity for the α3.7 deletion in a Pacific Island woman. Thalassemia Reports, 6(1). https://doi.org/10.4081/thal.2016.6044