The results confirmed that a highly conserved 500 Kb ancestral haplotype defined by the SNP markers PGBD1-A, ZNF193-A, ZNF165-T (A-A-T haplotype) marks the inheritance of "low" CD8+ T-lymphocyte numbers and predicts the development of a severe clinical expression of HH (in terms of iron overload and clinical manifestations). The gene discussed is ZNF165; the disease is Tangier disease.