A Novel Pathogenic ß-Thalassemia Mutation Identified at Codon 8 (HBB: c.27delG) in a Bangladeshi Family Acquired De Novo.

In Bangladesh, the practice of ß-thalassemia (ß-thal) carrier screening and prenatal diagnosis (PND) by ß-globin gene sequencing has been initiated to prevent the birth of affected children. The study aimed to describe a novel de novo mutation of the ß-globin gene and its clinical implication. Out of 100 Bangladeshi ß-thal carrier families, one patient with hematological and clinical features associated with ß-thal and her parents were included. Molecular characterizations of ß-globin gene mutations were performed by direct sequencing. A novel nucleotide deletion mutation at codon 8 in the first exon of the ß-globin gene (HBB: c.27delG) was found in a 1-year-old child of the studied family in a heterozygous state along with common Hb E (HBB: c.79G>A). The mutation caused a frameshift to a new stop codon at codon 18 resulting in a ß0-thal phenotype. The proband exhibited a ß-thal intermedia (ß-TI)-like genotype, however, showed ß-thal major (ß-TM)-like complications and was transfusion-dependent. Her mother had a profile consistent with the Hb E trait, while the father had normal hematological indices. Mutation analyses revealed the mother to be heterozygous for Hb E, while the father had a normal genotype. The novel mutation was assumed to be inherited de novo by the paternity test. The study documented a novel pathogenic mutation in the ß-globin gene in a Bangladeshi family by ß-globin gene sequencing.

Genetic polymorphism studies on 22 autosomal STR loci of the PowerPlex Fusion System in Bangladeshi population.

Genetic polymorphism of 22 autosomal STR loci included in PowerPlex® Fusion System (D3S1358, D1S1656, D2S441, D10S1248, D13S317, Penta E, D16S539, D18S51, D2S1338, CSF1PO, Penta D, TH01, vWA, D21S11, D7S820, D5S818, TPOX, D8S1179, D12S391, D19S433, FGA and D22S1045) was studied in 188 unrelated Bangladeshi Bengali individuals. Allele frequencies and forensic efficiency parameters such as, the power of discrimination (PD), observed and expected heterozygosity (Ho & He), polymorphism information content (PIC), probability of match (PM), power of exclusion (PE) and typical paternity index was calculated for the loci. The combined PM and PE for all 22 STR loci were calculated to be 5.29×10-27 and 0.99999999945 respectively. The dataset indicated the usefulness of these loci in personal identification, parentage testing and complex kinship analysis in Bangladeshi population. A neighbor-joining tree was constructed based on pair-wise Nei's genetic distance by comparing allele frequency data for the 22 loci with six other populations. The analysis showed that Bangladeshi population lies closer to a clade consisting Japan, the Philippines and East Timot populations.