Your Query returns 2 Accession Numbers:

Query TermAccessionNCBI TaxonidSynonymsPhenotype (OMIM) *
MRX79BC0116129606RTS    RTT    PPMX    MRX16    MECP2    300005
MRX79NM_0049929606RTS    RTT    PPMX    MRX16    MECP2    300005

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

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Text2Knowledge ... Yong Huang 2002