Which disorder has clinical features resembling Marfan syndrome, including dislocated lens and arachnodactyly?

Homocystinuria is a metabolic disorder that can present with clinical features resembling those of Marfan syndrome. This condition is caused by a deficiency of the enzyme cystathionine beta-synthase, leading to an accumulation of homocysteine in the body. The similarities between homocystinuria and Marfan syndrome include the presence of arachnodactyly (long, slender fingers) and lens dislocation, which can particularly occur in patients with homocystinuria due to the structural changes in connective tissues.

In addition to these physical features, individuals with homocystinuria may also experience developmental delays, skeletal abnormalities, and an increased risk of thromboembolic events, further differentiating their clinical presentation within the spectrum of connective tissue disorders. The identification of homocystinuria through urine tests detecting elevated levels of homocysteine and methionine supports the diagnosis, reinforcing the importance of distinguishing it from other disorders.

Maple syrup urine disease, alkaptonuria, and phenylketonuria are distinct metabolic disorders that have their own specific clinical manifestations and are not associated with lens dislocation or the classic skeletal features seen in Marfan syndrome.