A novel 506kb deletion causing εγδβ thalassemia.
We describe a novel deletion causing εγδβ thalassemia in a Pakistani family. The Pakistani deletion is 506kb in length, and the second largest εγδβ thalassemia deletion reported to date. It removes the entire β globin gene (HBB) cluster, extending from 431kb upstream to 75kb downstream of the ε globin gene (HBE). The breakpoint junction occurred within a 160bp palindrome embedded in LINE/LTR repeats, and contained a short (9bp) region of direct homology which may have contributed to the recombination event. Characterization of the deletion breakpoints has been particularly challenging due to the complexity of DNA deletion, insertion and inversion, involving a multitude of methodologies, mirroring the changing DNA analysis technologies.
King's College London, Molecular Haematology, James Black Centre, London SE5 9NU, UK.
Helen
H
Rooks
Barnaby
B
Clark
Steve
S
Best
Peter
P
Rushton
Matthew
M
Oakley
Onn Shaun
OS
Thein
Ann C
AC
Cuthbert
Alison
A
Britland
Afruj
A
Ruf
Swee Lay
SL
Thein
D000328:Adult; D001483:Base Sequence; D056905:Chromosome Breakpoints; D002880:Chromosomes, Human, Pair 11; D005260:Female; D059765:Homologous Recombination; D006801:Humans; D007223:Infant; D055029:Inverted Repeat Sequences; D020084:Long Interspersed Nucleotide Elements; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D055544:beta-Globins / Q000235:genetics*; D017086:beta-Thalassemia / Q000235:genetics*; D055546:delta-Globins / Q000235:genetics*; D055538:delta-Thalassemia / Q000235:genetics*; D055547:epsilon-Globins / Q000235:genetics*; D055545:gamma-Globins / Q000235:genetics*
D055544:beta-Globins; D055546:delta-Globins; D055547:epsilon-Globins; D055545:gamma-Globins