Molecular and hematologic characterization of Scottish-Irish type (εγδβ)° thalassemia

The DNA deletion associated with an example of (εγδβ)° thalassemia (Scottish-Irish type) was characterized. The deletion is approximately 205 kb in length and involves the ε, Gγ, Aγ, δ, and β globin genes. The breakpoint is located 263 bp 3' to exon 3 of the β globin gene. An LI (KpnI) repeat element approximately 320 bp in size is found at the 3' end of the novel DNA sequence. Different clinical phenotypes for three heterozygous neonates suggest that the deletion alone does not predict severity of (εγδβ)° thalassemia at this age.