XMNI GG-POLYMORPHISM IN SIX UNRELATED PAKISTANI FAMILIES WITH INV/DEL GG(AGDB) DB-THALASSEMIA

Authors: Suhaib Ahmed1* and Masood Anwar2
1 Department of Pathology, PNS Shifa, Karachi, Pakistan
2 Department of Haematology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan

The XmnI Gg-polymorphism (C–T polymorphism at position -158 to the Gg-globin gene)
was studied in 13 individuals from six unrelated Pakistani families with db-thalassemia.
All of the subjects had the Asian-Indian Inv/Del Gg(Agdb) that included six heterozygotes,
six homozygotes, and one compound heterozygote of db- and b-thalassemia. All seven
db-thalassemia heterozygotes (including one compound heterozygote) had the -/+ genotype,
whereas all six of the homozygotes had the +/+ genotype. The results strongly
suggest a tight linkage between the XmnI Gg-polymorphism and the Asian-Indian Inv/Del
Gg(Agdb). The finding could explain the unusually well-preserved capacity to produce
fetal hemoglobin in db-thalassemia. Am. J. Hematol. 80:303–305, 2005. ª 2005 Wiley-Liss, Inc.

Key words: The XmnI Gg-polymorphism (C–T polymorphism at position -158 to the Gg-globin gene)
was studied in 13 individuals from six unrelated Pakistani families with db-thalassemia.
All of the subjects had the Asian-Indian Inv/Del Gg(Agdb) that included six heterozygotes,
six homozygotes, and one compound heterozygote of db- and b-thalassemia. All seven
db-thalassemia heterozygotes (including one compound heterozygote) had the -/+ genotype,
whereas all six of the homozygotes had the +/+ genotype. The results strongly
suggest a tight linkage between the XmnI Gg-polymorphism and the Asian-Indian Inv/Del
Gg(Agdb). The finding could explain the unusually well-preserved capacity to produce
fetal hemoglobin in db-thalassemia. Am. J. Hematol. 80:303–305, 2005. ª 2005 Wiley-Liss, Inc.

Key words: db-thalassemia; XmnI polymorphism; Asian-Indian Inv/Del Gg(Agdb); Pakistan; XmnI polymorphism; Asian-Indian Inv/Del Gg(Agdb); Pakistan