The association of Hb khartoum [β124(H2)Pro→Arg] with γ⁺-thalassemia is responsible for hemolytic disease in the newborn of a sudanese family

Abstract

The unstable Hb Khartoum with a Pro→Arg replacement at position β124 was identified by isoelectrofocusing, high performance liquid chromatography, and peptide mapping in a mother and two male children of a Sudanese family. All three were heterozygous for the abnormal hemoglobin; the father and a third male child did not carry die mutation. The mother was also homozygous for two putative γ⁺-thalassemia point mutations, one affecting both ^Aγ and ^Gγ genes at IVS-II-115 (A→G), and one affecting the ^Gγ gene at the 3' untranslated region (-A) at position -6 from the polyadenylation site. The father had normal γ genes. All three children were heterozygous for both the γ⁺-thalassemia mutations. The two older children, who were compound heterozygotes for Hb Khar-toum/γ⁺-thalassemia, presented at birth with severe neonatal jaundice which necessitated exchange blood transfusions. Other causes of neonatal jaundice were excluded. The third male child, who did not carry the Hb Khartoum anomaly but was heterozygous for γ⁺-thalassemia, did not develop neonatal jaundice. It is concluded that the instability of Hb Khartoum in combination with γ⁺-thalassemia is responsible for neonatal hemolytic anemia in this family.

Key Words:

• Hb Khartoum
• γ-thal
• Sudan
• hemoglobinopathy
• unstable Hb
• point mutations

Additional information

Notes on contributors

P. Fitzgerald

Joyce Laing works in the Department of Child and Family Psychiatry, Playfield House, Cupar, Fife, and is a Consultant Art Therapist to Psychiatric Hospitals and Prisons and Chairwoman of the Scottish Society of Art and Psychology.