Related articles: Marfan syndrome
Definition
Marfan syndrome is a systemic disease characterized by an abnormality of connective tissue, which causes cardiovascular, musculoskeletal, ocular and pulmonary changes.
This disease is generally transmitted in an autosomal dominant manner (ie the parent affected by the disease has a 50% chance of transmitting Marfan syndrome to each of their children), but sporadic forms have also been described.
In most cases, Marfan syndrome is caused by mutations in the gene located on chromosome 15 (15q21), which encodes fibrillin-1 (FBN1), an essential connective tissue protein.
Marfan syndrome manifests itself in a highly variable association of symptoms. In general, the most obvious clinical signs are the cardiovascular system, the musculoskeletal system and the eyes.
Most common symptoms and signs *
- Eye fatigue
- arachnodactyly
- Arrhythmia
- Bladder dysfunction
- Dyspnoea
- dolichocephaly
- Chest pain
- Foot pain
- Bruising
- enophthalmos
- Fecal incontinence
- hyperkyphosis
- Joint hypermobility
- Iridodonesi
- Backache
- Headache
- Dental malocclusion
- micrognathia
- Ogival palate
- Carinated breast
- pneumothorax
- Reduced vision
- Skin sclerosis
- Scoliosis
- Heart murmur
- Funnel chest
- Blurred vision
Further indications
Marfan syndrome is typically recognized on the basis of the proportionally longer limbs of the trunk (habitus longilineo), the aortic dilation and the dislocation of the lens (characteristic signs are ectopia or dislocation of this ocular structure).
In many cases, the involvement of the cardiovascular system involves the prolapse or insufficiency of the mitral valve and progressive dilation of the aorta. This last eventuality can result in an aneurysm and dissect itself acutely, sometimes even before the age of 10 years. Mitral valve insufficiency can be complicated by arrhythmias, endocarditis or heart failure.
The musculoskeletal system is affected with a severity that varies greatly. Patients with Marfan syndrome have a very high stature (compared to age and family), a lanky appearance (ie movements are loose, but uncoordinated), arachnodactyly (slender and long fingers), overly mobile joints (which predispose to dislocations) and alterations of the spine. Malformations of the sternum are frequent, such as the chested chest (protrusion of the chest wall) or the pectus excavatum (hollowing of the distal part of the sternum). The palate is often ogival (narrow and high).
The laxity of the connective tissue can also determine kyphoscoliosis, diaphragmatic and inguinal hernias, and flat feet. Furthermore, cutaneous signs (stretch marks) may be present. Severe scoliosis can cause chronic back pain.
At the ocular level, Marfan syndrome manifests itself with crystalline ectopia (subluxation or dislocation with upward displacement), which loses its seat due to the laxity of the ligaments. Other signs include iridodonesi (iris shake) and high-grade myopia. Sometimes, a spontaneous retinal detachment may occur.
The pulmonary system and the central nervous system (CNS) are also affected. In particular, cystic pneumopathy and spontaneous recurrent pneumothorax may arise. These disorders are responsible for pain and shortness of breath. A frequent finding indicating the involvement of the CNS, on the other hand, is the ectasia of the dura mater (ie the enlargement of the dural sac that surrounds the spinal cord), especially at the level of the lumbo-sacral column. Possible consequences are headache, low back pain or neurological deficits that occur with intestinal or bladder weakness.
The diagnosis is based on the presence of certain clinical criteria and on the execution of instrumental tests that ascertain characteristic abnormalities of Marfan syndrome, including: echocardiography, slit-lamp examination and magnetic resonance.
