Neil Risch et al. in Correspondence1 state that our paper2 on the genetic relatedness of Palestinians and Jews lacked scientific merit because its conclusions are based on data reported for a single-locus genetic marker (HLA-DRB1). Although the use of single-locus markers can lead to misleading results, single-locus studies, whether using HLA or other markers, are common in this field and are regularly published in the specialist literature.

In papers reporting data on a single locus, it is important not to take anomalous results at face value but to interpret them in the light of other types of data, such as historical, anthropological and linguistic data, as well as testing them using other genetic markers (see, for example, ref. 3). As we stated in ref. 2, we are currently investigating the populations reported in our paper using other markers.