As the frequency of homozygous TT genotype was low, we intended to divide the HF patients into two group, those having AA genotype alone (AA genotype group) and those with AT and TT genotype (AT/TT genotype group), to study the influence of GRK5 Gln41Leu (rs17098707) polymorphism on response to β-blocker therapy in the HF patients. Here, GRK5 is linked to hydrops fetalis.