title: Characterization of Clinical and Laboratory Profiles of the Deletional α2-Globin Gene Polyadenylation Signal Sequence (AATAAA > AATA- -) in an Indian Population.
abstract: α-Thalassemia (α-thal) is characterized by large deletions involving the variable regions of α2 and/or α1 genes. Nondeletional mutations and polyadenylation (polyA) signal sequence motif mutations are less common. In this retrospective study, we describe a fragment length analysis-based polymerase chain reaction (PCR) assay for screening the T(Indian) (AATAAA > AATA- -; HBA2: c.*93_*94delAA) polyA signal deletion along with its clinical and laboratory presentation in 21 patients. Most of the patients were diagnosed in early adulthood with a clinical presentation ranging from asymptomatic in the heterozygous state to severe Hb H disease with a prominent hemolytic component in the homozygous state. On genetic analysis, 14 patients were found to be homozygotes, five were compound heterozygotes and two were heterozygotes. Thus, the T(Indian) polyA signal deletion is common in the Indian population and should be screened for in patients with nondeletional α-thal mutations.
authors.affiliation: a Department of Haematology , Christian Medical College , Vellore , Tamil Nadu , India.
authors.forename: Prashant
authors.initials: P
authors.lastname: Deshpande
authors.affiliation: a Department of Haematology , Christian Medical College , Vellore , Tamil Nadu , India.
authors.forename: Neelagandan
authors.initials: N
authors.lastname: Kamalanathan
authors.affiliation: a Department of Haematology , Christian Medical College , Vellore , Tamil Nadu , India.
authors.forename: Eswari
authors.initials: E
authors.lastname: Sampath
authors.affiliation: a Department of Haematology , Christian Medical College , Vellore , Tamil Nadu , India.
authors.forename: Biju
authors.initials: B
authors.lastname: George
authors.affiliation: a Department of Haematology , Christian Medical College , Vellore , Tamil Nadu , India.
authors.forename: Ramachandran V
authors.initials: RV
authors.lastname: Shaji
authors.affiliation: a Department of Haematology , Christian Medical College , Vellore , Tamil Nadu , India.
authors.forename: Eunice S
authors.initials: ES
authors.lastname: Edison
mesh_terms: D020413:3' Untranslated Regions; D004252:DNA Mutational Analysis; D004909:Erythrocyte Indices; D005260:Female; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D010641:Phenotype; D011061:Poly A; D011159:Population Surveillance; D017384:Sequence Deletion; D055542:alpha-Globins / Q000235:genetics*; D017085:alpha-Thalassemia / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; D055542:alpha-Globins; D011061:Poly A
keywords: Nondeletional α-thalassemia (α-thal); Polyadenylation (polyA) signal mutation; TIndian polyA signal deletion