Molecular characterisation of a hypervariable region downstream of the human alpha‐globin gene cluster.

We have characterised an unusual, highly polymorphic region of DNA located 8‐kb downstream of the human alpha‐globin gene complex. This hypervariable region (alpha‐globin 3′ HVR) is composed of an array of 17‐bp tandem repeats, the number of which differs considerably (70‐450) from one allele to another. The sequence of the 17‐bp repeats is highly conserved within and between alleles. Furthermore, this sequence identifies a core oligonucleotide [5′‐GNGGGG(N)ACAG‐3′] that is common to three previously characterised hypervariable regions. At reduced stringency, a probe to the 3′ HVR detects a new family of multiallelic loci that will be of value in the study of human genetics.