A 13-year-old male is brought to his pediatrician for evaluation. The parents are concerned after the patient’s swim coach noticed that the patient’s chest “does not look normal.” Upon questioning, the patient has no particular complaints. However, during a review of systems, he admits to some recent blurring of his vision, requiring him to sit in the front of his classes. On exam, he is noted to have a tall stature with long limbs. He is able to hyperextend the elbows and can flex his fingers and wrists far enough to touch his forearms. He has a noticeable pectus deformity of the chest. The inheritance pattern of his condition is:
A. Autosomal dominant
B. Autosomal recessive
C. Duplicated chromosome
D. X-linked dominant
E. X-linked recessive
Answer …show more content…
This patient has Marfan syndrome. This condition arises from an autosomal dominant mutation in the gene for the fibrillin-1 protein. Patients with Marfan syndrome are generally of tall stature with long limbs. Their joints are hypermobile, which can be assessed by asking patients to extend their elbows and observing hyperextension. Hypermobility at the wrists is observed by asking the patient to touch the volar or anterior surface of the forearm with their fingers. Through hyperflexion of the wrists, these patients will often be able to touch their forearms. Other features of Marfan syndrome include kyphosis of the spine, pectus deformities, lens subluxation, aortic root dilation, and aortic dissection. Marfan syndrome is not associated with any intellectual disability. Some other autosomal dominant disorders include: Huntington chorea, chondroplasia, Ehlers-Danlos, adult-onset polycystic kidney disease, neurofibromatosis, and hereditary
A. Autosomal dominant
B. Autosomal recessive
C. Duplicated chromosome
D. X-linked dominant
E. X-linked recessive
Answer …show more content…
This patient has Marfan syndrome. This condition arises from an autosomal dominant mutation in the gene for the fibrillin-1 protein. Patients with Marfan syndrome are generally of tall stature with long limbs. Their joints are hypermobile, which can be assessed by asking patients to extend their elbows and observing hyperextension. Hypermobility at the wrists is observed by asking the patient to touch the volar or anterior surface of the forearm with their fingers. Through hyperflexion of the wrists, these patients will often be able to touch their forearms. Other features of Marfan syndrome include kyphosis of the spine, pectus deformities, lens subluxation, aortic root dilation, and aortic dissection. Marfan syndrome is not associated with any intellectual disability. Some other autosomal dominant disorders include: Huntington chorea, chondroplasia, Ehlers-Danlos, adult-onset polycystic kidney disease, neurofibromatosis, and hereditary