COMP and pseudoachondroplasia: As a result of recent findings describing neuromuscular-like symptoms in T3-COMP and possibly MATN3 patients [9,26], we wished to characterise the muscle and tendon phenotype in two further mouse models of the PSACH/MED spectrum; the Comp ΔD469 [22] and Matn3 V194D [34] models of severe PSACH and moderate MED respectively.