Marfan syndrome


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Marfan syndrome

Disease-specific pathology

Cardiovascular disorders


Aortic valve disease

Atherosclerosis and arteriosclerosis: Pathology review

Atrial septal defect

Cardiac and vascular tumors: Pathology review

Cor pulmonale

Dyslipidemias: Pathology review

Heart failure

Heart failure: Pathology review

Mitral valve disease

Patent ductus arteriosus

Pulmonary embolism

Pulmonary hypertension

Vasculitis: Pathology review

Ventricular septal defect

Endocrine disorders

Adrenal masses: Pathology review

Multiple endocrine neoplasia: Pathology review

Neuroendocrine tumors of the gastrointestinal system: Pathology review

Pituitary tumors: Pathology review

Thyroid nodules and thyroid cancer: Pathology review

Eye, ear, nose, and throat disorders

Eye conditions: Inflammation, infections and trauma: Pathology review

Eye conditions: Retinal disorders: Pathology review

Nasal, oral and pharyngeal diseases: Pathology review

Thyroid nodules and thyroid cancer: Pathology review

Vertigo: Pathology review

Gastrointestinal disorders

Diverticulosis and diverticulitis


Esophageal disorders: Pathology review

Gastrointestinal bleeding: Pathology review


Malabsorption syndromes: Pathology review

Neuroendocrine tumors of the gastrointestinal system: Pathology review

Genetic disorders

Angelman syndrome

Down syndrome (Trisomy 21)

Edwards syndrome (Trisomy 18)

Ehlers-Danlos syndrome

Fragile X syndrome

Klinefelter syndrome


Marfan syndrome

Myotonic dystrophy


Osteogenesis imperfecta

Patau syndrome (Trisomy 13)

Prader-Willi syndrome

Sickle cell disease (NORD)

Turner syndrome

Hematological disorders

Blood transfusion reactions and transplant rejection: Pathology review

Metabolic acidosis

Metabolic alkalosis

Non-hemolytic normocytic anemia: Pathology review

Platelet disorders: Pathology review

Respiratory acidosis

Respiratory alkalosis

Thrombosis syndromes (hypercoagulability): Pathology review

Integumentary disorders

Pigmentation skin disorders: Pathology review

Papulosquamous and inflammatory skin disorders: Pathology review

Vesiculobullous and desquamating skin disorders: Pathology review

Metabolic disorders


Glucose-6-phosphate dehydrogenase (G6PD) deficiency



Lactose intolerance

Metabolic acidosis

Metabolic alkalosis

Phenylketonuria (NORD)

Tay-Sachs disease (NORD)

Musculoskeletal disorders

Back pain: Pathology review

Seronegative and septic arthritis: Pathology review

Myalgias and myositis: Pathology review

Neurodevelopmental disorders

Disruptive, impulse control, and conduct disorders

Fetal alcohol syndrome

Learning disability

Shaken baby syndrome

Tourette syndrome

Neurologic disorders

Alzheimer disease

Headaches: Pathology review

Traumatic brain injury: Pathology review

Spina bifida

Nutritional disorders


Excess Vitamin A

Excess Vitamin D

Folate (Vitamin B9) deficiency

Iodine deficiency



Niacin (Vitamin B3) deficiency

Vitamin B12 deficiency

Vitamin C deficiency

Vitamin D deficiency

Vitamin K deficiency

Wernicke-Korsakoff syndrome

Zinc deficiency

Psychiatric disorders


Bipolar disorder

Body dysmorphic disorder

Body focused repetitive disorders

Cluster A personality disorders

Cluster B personality disorders

Cluster C personality disorders

Delusional disorder

Dissociative disorders

Factitious disorder

Major depressive disorder

Neuroleptic malignant syndrome


Premenstrual dysphoric disorder

Schizoaffective disorder

Schizophreniform disorder

Seasonal affective disorder

Serotonin syndrome

Somatic symptom disorder

Renal disorders




Metabolic acidosis

Metabolic alkalosis

Poststreptococcal glomerulonephritis

Prerenal azotemia

Respiratory disorders

Chronic bronchitis

Cor pulmonale



Pulmonary embolism

Respiratory acidosis

Respiratory alkalosis

Sexual and reproductive disorders

Amenorrhea: Pathology Review

Benign breast conditions: Pathology review

Disorders of sex chromosomes: Pathology review

Erectile dysfunction

Female sexual interest and arousal disorder

Genito-pelvic pain and penetration disorder

Male hypoactive sexual desire disorder

Orgasmic dysfunction

Penile conditions: Pathology review

Testicular and scrotal conditions: Pathology review

Uterine disorders: Pathology review

Vaginal and vulvar disorders: Pathology review

Sleep disorders



Narcolepsy (NORD)

Night terrors


Marfan syndrome


0 / 11 complete

USMLE® Step 1 questions

0 / 2 complete

High Yield Notes

6 pages


Marfan syndrome

of complete


USMLE® Step 1 style questions USMLE

of complete

A 25-year-old woman comes to an outpatient clinic to establish care. The patient has not seen a physician in several years but overall feels healthy except for blurry vision. She attributes this symptom to myopia caused by “spending too many hours in front of the laptop.” Past medical history is significant for pelvic inflammatory disease successfully treated with antibiotics. The patient was adopted as a young child and has never met her biological parents. Vitals are within normal limits. Slit-lamp examination is notable for bilateral upward lens subluxation. Physical examination reveals a patient at the 90th percentile for height and 50th percentile for weight. The patient also has long, tapering fingers and a prominent, protruding sternum. Oropharyngeal examination shows a high-arched palate with crowded teeth. This patient is most likely to develop which of the following complications?

External References

First Aid








Aortic aneurysm p. 308

Marfan syndrome p. 50, 306

Aortic dissection p. 309

Marfan syndrome p. 714

Marfan syndrome as cause p. 306

Aortic regurgitation

Marfan syndrome p. 306

Arachnodactyly p. 50

Marfan syndrome p. 714

Marfan syndrome

aortic aneurysms p. 728

aortic dissection and p. 309

cardiac defect association p. 306

cataracts p. 554

chromosome association p. 62

elastin and p. 50

heart murmur with p. 298

presentation p. 714

thoracic aortic aneurysms and p. 308


Content Reviewers

Rishi Desai, MD, MPH


Tanner Marshall, MS

Marfan syndrome is a genetic disorder that results in defective connective tissue, which can affect a person’s skeleton, heart, blood vessels, eyes, and lungs.

Normally, the interstitial space of various body tissues is full of microfibrils - which are strong rope-like structures that provide tissue integrity and form connective tissue.

Each microfibril is made of cellulose as well as glycoproteins including the protein fibrillin. In some structures microfibrils form a scaffold for additional proteins like elastin.

Elastin fibers are highly cross-linked, and that gives them a rubber-band-like quality, which allows tissues to stretch and then spring back to their original shape.

Tissues that have elastin fibers are the arteries, skin, and lungs, and tissues that have microfibrils but no overlying layer of elastin are like tendons and the ciliary zonules that hold the eye lens in place.

These tissues are less stretchable, but still have considerable tensile strength.

In addition to being part of microfibrils, fibrillin also regulates tissue growth.

Fibrillin sequesters or removes transforming growth factor beta, or TGF-β, which stimulates tissue growth, so fibrillin therefore lowers how much TGF-β is available to stimulate growth.

Marfan syndrome is caused by mutations in a gene called FBN1, or fibrillin 1, on chromosome 15.

It’s autosomal dominant, which means that even if there’s a normal copy of the gene, a single mutated copy of the gene – in other words a heterozygous mutation – is sufficient to cause the disease.

The FBN1 gene encodes Fibrillin-1 protein, one of three fibrillin subtypes.

In Marfan syndrome, fibrillin-1 is either less abundant or it is dysfunctional. As a result, there are fewer functioning microfibrils in the extracellular matrix, and that means there’s less tissue integrity and elasticity.

Connective tissue is found throughout the body, so this can affect nearly every body system.

Additionally, TGF-β doesn’t get effectively sequestered, so TGF-β signaling is excessive in these tissues - meaning more growth.

The most obvious physical features of Marfan syndrome involve the skeleton.

The long bones grow excessively, so individuals are tall with long arms and legs – this is called a Marfanoid body habitus.


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