To address this discrepancy, this study used <i>Gucy1a3</i> loss‐of‐function mice (<i>Gucy1a3</i> <sup>-/-</sup>) to investigate the potential causal relationship between <i>GUCY1A3</i> loss‐of‐function and the cerebrovascular phenotype in MMD.<h4>Methods</h4>Intracranial arterial anatomy was assessed using 7.0T high‐resolution magnetic resonance angiography (MRA) and cerebral vascular casting. This evidence concerns the gene GUCY1A1 and multiminicore myopathy.