Microcytic Anemia in Hemoglobin H Disease Concealed with Hemoglobin Hope Trait: A Case Report

Abstract

Hemoglobin Hope is one of beta hemoglobinopathies [alpha2beta2
136 gly→asp (GGT→GAT)]. Hb Hope trait or
disease has been occasionally reported worldwide and is the third common beta hemoglobinopathy after Hb E
and Hb C in Thailand. Herein we report a case of Hb Hope trait in combination with Hb H disease that has
never been presented. She was a 17-year-old Thai woman who had been recognized as anemic since young
childhood. Five years ago, her blood tests were: Hb 8.5 g/dL, MCV 48.5 fL, reticulocyte 1.42%, serum ferritin 103.7
ng/mL, Hb analysis: Hb A2A and abnormal Hb later proved to be Hb Hope. She received a diagnosis of Hb Hope
trait with unresolved moderately severe microcytic anemia because Hb Hope trait alone should be clinically and
laboratory normal. After the parents were tested they were found to have alpha thalassemia-2 genes, both 3.7
and 4.2 kb deletions in the father and a combination of Hb E 24.2%, Hb Hope 74.9% and alpha thalassemia-1
trait, SEA deletion in the mother. The patient was tested again and found to have Hb A2A, Hb A2 3.1%, Hb
Hope 22.3%, alpha thalassemia-1 (SEA deletion) and alpha thalassemia-2 (4.2 kb deletion). Therefore, she was
definitely diagnosed as Hb H disease co-inherited with Hb Hope trait. The diagnosis of the part of Hb H disease
in our patient was delayed for five years because of the disappearance of Hb H or Hb Barts on Hb analyses and
the unavailability of the DNA analysis. Moreover, our case showed although Hb Hope in heterozygosity and
homozygosity are always clinically and hematologically silent, when co-inherited with Hb H disease, it can produce
more severe anemia and more prominent microcytosis, as compared with Hb H disease with or without
Hb E trait.