Prior art — US Patent 7267820

To identify the most relevant prior art for US Patent 7267820, I will search the USPTO database for the patent and then analyze its cited references.

Here's the analysis of the most relevant patent prior art for US Patent 7267820, as listed in the patent document itself:

Full Citation: US 5,814,478 A (Regeneron Pharmaceuticals, Inc.)
Publication Date: September 29, 1998
Filing Date: December 15, 1995
Brief Description: This patent describes tyrosine kinase receptors and their ligands. It covers the identification, isolation, and use of these receptors and ligands, particularly in the context of cell growth, differentiation, and development. Since MuSK is a receptor tyrosine kinase (RTK), this patent generally covers the class of molecules to which MuSK belongs and methods for studying them.
Potential Anticipation (35 U.S.C. § 102): This patent broadly covers receptor tyrosine kinases. While it doesn't specifically mention MuSK or its autoantibodies, it establishes the prior art for the general concept of studying RTKs and their role in biological processes. It could potentially anticipate the broader aspects of the invention related to the use of RTKs as targets in diagnostic methods, particularly for claims that are not narrowly focused on the specific MuSK autoantibody detection (e.g., portions of claim 1, 2, and 7 if interpreted very broadly outside the MuSK-specific autoantibody detection). However, the novelty of US7267820 lies in the discovery of autoantibodies to MuSK as a diagnostic marker for specific neurotransmission disorders, which this patent does not disclose.

Full Citation: WO 1999/010494 A2 (Genentech, Inc.)
Publication Date: March 4, 1999
Filing Date: August 25, 1997
Brief Description: This international publication describes agonist antibodies that bind to and activate the thrombopoietin receptor, and their therapeutic uses. It demonstrates the concept of using antibodies to modulate receptor activity for therapeutic purposes.
Potential Anticipation (35 U.S.C. § 102): This reference teaches the use of antibodies as diagnostic and therapeutic agents targeting a receptor. While it specifically concerns the thrombopoietin receptor and agonist antibodies, it establishes the prior art for the general idea of using antibodies to detect or treat conditions related to receptor function. This could potentially anticipate aspects of US7267820 related to the general methodology of antibody-based diagnostics or therapeutics for receptor-related disorders (e.g., claims 1, 2, 7, and the concept of an isolated antibody in the description for treatment, if interpreted broadly). However, it does not disclose the specific target (MuSK), the specific type of antibody (autoantibody), or the specific disorders (neurotransmission/developmental disorders related to MuSK) found in US7267820. The key inventive step of US7267820 is the identification of anti-MuSK autoantibodies in the context of specific disorders.