MYH11 and Marfan syndrome: An initial clinical suspicion of MFS due to joint hypermobility at 3 years of age became a definitive diagnosis after an external laboratory reported a heterozygous variant in the <i>MYH11</i> gene at age 5, despite the patient never fulfilling the established clinical diagnostic criteria for the disease.<h4>Methods</h4>To provide an accurate diagnosis and end the family's diagnostic odyssey, a complete clinical and genetic reinterpretation was performed when the patient was 7 years old.