Your Query returns 2 Accession Numbers:

Query TermAccessionNCBI TaxonidSynonymsPhenotype (OMIM) *
ER[a]NM_1529597955ESR    NR3A1    zfER[a]    esr1   
ER[a]NM_00795610090ERa    ESR    Estr    Estra    Nr3a1    ERalpha    Esr1   

Search Again
* OMIM link based on symbol match for human and mouse.

Google

Text2Knowledge ... Yong Huang 2002