[Minor beta thalassemia masked by a hemoglobin A2 mutant]

The elevation of hemoglobin A2 [HbA2] is an essential criterion in the diagnosis of minor beta thalassemia. To report a case of minor beta thalassemia HbA2 with normal HbA2 rate. We report the case of ten years old boy, with hypochromic microcytic anemia, refractory to iron treatment. The study of hemoglobin [Hb] has revealed the presence of a minor abnormal fraction of Hb, amounted to 2.8%, associated with the presence of HbF and normal levels of HbA2. Family study revealed the presence of two Hb abnormalities [beta thalassemia trait and HbA2 mutant] transmitted to offspring in isolation or associated. The genotypic study confirmed the presence of minor, 0 thalassemia and a% gene mutation, causing a new mutant HbA2 named HbA2 Pasteur-Tunis [%59 [E3] Lys [rightwards arrow] Asn [AAG [rightwards arrow] AAC]]. The presence of% mutant reduces HbA2 level and could hide beta thalassemia trait. Rigorous and methodical interpretation of phenotypic data is crucial to not overlook the presence of beta thalassemia trait, whose diagnosis is crucial for genetic counseling and prenatal diagnosis

Haematological and molecular aspects of hemoglobinosis H: about three Tunisian cases

Hemoglobinosis H is the severest alpha-thalassemia compatible with life. The clinical manifestation seems to be different regarding to the genotype. The present paper aims to provide to hematological and molecular data related to three patients suffering from hemoglobinosis H alpha thalassemia and their family. The clinical and biological profiles appear to be similar to those observed in thalassemia intermedia with mild hemolytic microcytic anemia. The diagnosis was based on decreased Hb A2 level [< 2%] and the presence of Hb H at an amount ranging from 10 to 30%. Two different molecular defects were observed. The genotypes were an association of two types of deletion [--MEDI an alpha [3.7]] and two point mutations [alpha[snt] and alpha t], The correlation phenotype / genotype showed that non-deletional Hb H is more severe than deletional forms. Detection of athalassemia trait remains difficult, it's detection is yet a matter of exclusion diagnosis based on the observation of isolated microcytosis with normal or limited Hb A2 levels with a normal iron state. Molecular study is a powerful tool for the diagnosis of such alpha cases