Which genetic condition is associated with a mutation in the fibrillin-1 gene?

Marfan syndrome is associated with a mutation in the fibrillin-1 gene (FBN1), which plays a crucial role in the formation of elastic fibers in connective tissue. This genetic condition is characterized by findings such as tall stature, long limbs and fingers (arachnodactyly), cardiovascular abnormalities (especially aortic dilation and regurgitation), and ocular manifestations (such as lens dislocation). The defect in fibrillin-1 disrupts the integrity and function of connective tissues, leading to the diverse clinical features seen in individuals with Marfan syndrome.

In contrast, Turner syndrome is caused by a chromosomal abnormality resulting in the loss of one X chromosome, Down syndrome is a genetic condition caused by the presence of an extra chromosome 21 (trisomy 21), and neurofibromatosis is linked to mutations in the NF1 or NF2 genes, which are unrelated to fibrillin-1. Understanding the specific genetic basis of these conditions helps in accurately identifying and managing them clinically.