Reactive arthritis (ReA) is a sterile inflammatory arthritis that follows an infection at a different site, commonly enteric or urogenital. It is classified as a type of seronegative spondyloarthropathy.
Reactive arthritis was formerly known as Reiter syndrome/disease, which is the...
Renal cysts and diabetes syndrome (RCAD), also known as maturity-onset diabetes of the young, type 5 (MODY5), refers to the combination of renal cortical cysts and diabetes mellitus in patients with mutations in the HNF1B gene. When renal cysts are associated with these mutations without disturb...
Rett syndrome is a rare neurodegenerative disease seen in young girls in the 2nd to 4th months of life. The majority of cases result from a mutation in the MECP2 gene; a more severe subset of the disease arises from a CDKL5 mutation1.
Following a period of normal develop...
Rhupus syndrome is a term traditionally used to describe patients uncommonly having the coexistence of
systemic lupus erythematosus (SLE) and
rheumatoid arthritis (RA)
The Rieger anomaly refers to the maldevelopment of the anterior chamber of the ocular globe. The iris and cornea do not form correctly, findings including:
hypoplastic iris stroma
corectopia: an off-center pupil in the iris
colobomas of the iris (pseudopolycoria)
Patients are at increased ri...
Right middle lobe syndrome refers to chronic right middle lobe collapse, without an obstructing lesion. It is usually with associated bronchiectasis.
Right middle lobe syndrome is usually encountered in older adults, with a predilection for women (see Lady Windermere syndrome). I...
Ritscher-Schinzel syndrome (RTSC), also known as 3C (cranio-cerebello-cardiac) syndrome, is a rare entity with a variable spectrum of CNS (primarily cerebellar), craniofacial, and congenital heart defects.
Roberts syndrome, also known as Roberts-SC phocomelia syndrome, pseudothalidomide syndrome, or Appelt-Gerken-Lenz syndrome, is a rare congenital malformation syndrome.
intrauterine growth restriction
postnatal growth retardation
failure to thrive
Robinow syndrome is a rare heterogenous genetic disorder with at least two distinct forms.
The syndrome can affects several systems which include:
mesomelic limb shortening: mesomelia
characteristic facies anomalies
Rosai-Dorfman disease, also known as sinus histiocytosis with massive lymphadenopathy, is a rare benign idiopathic proliferative disease that involves phagocytic histiocytes.
The disease predominantly occurs in young adults with a mean age at presentation of 21 years. There may be...
Rotational vertebral artery occlusion syndrome, also known as bow hunter's syndrome, is a rare form of vertebrobasilar insufficiency secondary to dynamic compression of the usually-dominant vertebral artery.
It has many predisposing etiologies, but is most often due to large osteoph...
Rubinstein-Taybi syndrome (RTS) is a very rare genetic multi-system disorder primarily characterized by mental retardation, broad and often angulated thumbs and halluces, and distinctive facial features.
The estimated incidence is 1 in 100,000-125,000 live births 5.
Russell-Silver dwarfism is a very rare syndrome characterized by:
intrauterine growth restriction: tends to give an asymmetrical IUGR
postnatal growth restriction
relatively large calvarium: pseudohydrocephalus
clinodactyly/clinobrachydactyly of the small finger
a typical triangular type fa...
Ruvalcaba syndrome (also known as Ruvalcaba-Myhre-Smith syndrome) is one of a group of disorders related to congenital skeletal disturbance. It is characterized by:
mental (not invariably) and physical retardation
SADDAN syndrome is an acronym for severe achondroplasia with developmental delay and acanthosis nigricans. It is an extremely rare condition, and as the name states, comprises a combination of skeletal, brain and cutaneous anomalies.
The syndrome results from a mutation in ...
The Sakati-Nyhan syndrome, also known as Sakati-Nyhan-Tisdale syndrome or acrocephalosyndactly type III, is an extremely rare type of acrocephalopolysyndactyly.
Its main features include:
congenital limb abnormalities
congenital heart defects
History and etymology
Sampson syndrome refers to a type of superficial endometriosis, where multiple superficial plaques may be seen scattered in the peritoneum and pelvic ligaments.
The patient may present with non-specific abdominal pain.
At laparoscopy, they are typi...
The SAPHO syndrome is an acronym that refers to a rare condition that is manifested by a combined occurrence of 2
It classically tends to present in young to middle-aged adults. Presentation in the pediatric popu...
Schimmelpenning syndrome is a rare and variable congenital multisystem condition characterized by extensive linear sebaceous nevi and multisystem neuroectodermal abnormalities. It is an epidermal nevus syndrome (ENS).
Classical triad including sebaceous nevi, seizures, an...
Sclerosteosis is a rare autosomal recessive bone dysplasia resulting in sclerosis and hyperostosis, particularly of the skull, mandible and tubular bones. It is closely related to Van Buchem disease 1.
Sclerosteosis is a very rare disease, with only around 100 cases reported. Ther...
The seatbelt syndrome is the constellation of traumatic injuries associated with three-point seatbelts:
lumbar spine fracture
Seckel syndrome is an autosomal recessive congenital dwarfing disorder.
The estimated incidence is ~1:10,000. There is no recognised gender predilection.
It is clinically characterized by many features including:
intrauterine growth restriction
Segmental arterial mediolysis (SAM) is an increasingly recognised vascular disease of the middle-aged and elderly and a leading cause of spontanoeus intra-abdominal hemorrhage. It is characterized by fusiform aneurysms, stenoses, dissections and occlusions within splanchnic arterial branches. Im...
Serrated polyposis syndrome (SPS), also called hyperplastic polyposis syndrome, is one of numerous polyposis syndromes and is characterized by the presence of multiple serrated polyps or a mixture of serrated and hyperplastic polyps, with the exact number required for diagnosis dependent on loca...
Sézary syndrome (SS) is a type of cutaneous T-cell lymphoma. It is sometimes considered an advanced and leukemic form of cutaneous T-cell lymphoma (CTCL).
It is clinically characterized by an extensive erythematous rash covering most of the body as well as the presence of...
Sheehan syndrome is a rare cause of pituitary apoplexy and hypopituitarism. It only occurs in postpartum females who experience large volume hemorrhage and hypovolemic shock, either during delivery or afterwards.
pituitary failure 1
may be silent and present with delayed...
Shone syndrome, also known as Shone complex, is a rare syndrome characterized by left-sided, obstructive congenital heart defects.
Shone syndrome is thought to be very rare, accounting for less than 1% of all congenital heart disease 1.
Patients, usually ne...
Short rib polydactyly syndrome(s) (SRPS) comprise a rare group of severe osteochondrodysplasias. There are four major recognised types present:
type I: Saldino-Noonan type
type II:: Majewski type
type III: Verma-Naumoff type
type IV: Beemer-Langer type
There may also be other very rare type...
SHORT syndrome refers to an acronym which primarily comprises of the following features:
S: short stature
H: hyperextensibility of joints and/or inguinal hernia
O: ocular depression
R: Rieger anomaly
T: teething delay
In a addition to these there can be numerous associated minor features w...
The Shwachman-Diamond syndrome (SDS) or Shwachman-Bodian-Diamond syndrome (SBDS) is a rare autosomal recessive disorder characterized by 1 :
exocrine pancreatic insufficiency
bone marrow hypoplasia (cyclic neutropenia)
Patients with Shwachman-...
The Shy-Drager syndrome is a neurodegenerative disease, and one of the manifestations of multiple systemic atrophy (MSA).
It is important to note that the current belief that olivopontocerebellar degeneration, Shy-Drager syndrome and striatonigral degeneration are different manifes...
Acute chest syndrome (ACS) in sickle cell disease is a leading thoracic complication - as well as leading cause of mortality - in those affected by sickle cell disease. The diagnosis is made on the combination of new pulmonary opacity on chest x-ray with at least one new clinical symptom or sign...
The silent sinus syndrome represents maxillary sinus atelectasis that results in painless enophthalmos, hypoglobus and facial asymmetry 1-3. Some authors restrict the term to patients with no history of sinusitis, trauma or surgery 2.
Silent sinus syndrome usually presents in the ...
Sinus tarsi syndrome (STS) is the clinical syndrome of pain and tenderness of the lateral side of the hindfoot, between the ankle and the heel. Imaging often demonstrates the ligaments and soft tissues in the sinus tarsi are injured.
Sinus tarsi syndrome has been described in danc...
Sjögren syndrome, or Sjögren disease, is an autoimmune condition of the exocrine glands that produce tears and saliva.
Sjögren syndrome is the second most common autoimmune disorder after rheumatoid arthritis. There is a recognised female predilection with F:M ratio of ≈9:1. Pati...
Slit ventricle syndrome refers to cerebrospinal fluid shunt-related symptoms in the setting of small ventricles demonstrated on radiologic studies.
The presence of characteristic symptoms is required to diagnose slit-ventricle syndrome and must be distinguished from slit-...
SMART syndrome, an acronym for stroke-like migraine attacks after radiation therapy, is an uncommon delayed complication of cerebral radiation therapy.
Patients usually present years after radiation therapy (6-30 years in a case series) with seizures and subacute stroke-l...
Smith-Lemli-Opitz syndrome (SLOS) also known as 7-dehydrocholesterol reductase deficiency is an inborn error of cholesterol synthesis.
The estimated incidence is at 1:20000-40000 live births. Prevalence may be greater in Nordic countries.
There are many wh...
Smith-Magenis Syndrome (SMS) is a rare genetic syndrome which results from an interstitial deletion in chromosome 17p11.2.
The condition is known by several other names which are all similar variants related to its underlying karyotype: 17p deletion syndrome, 17p11.2 monosomy, chro...
Snapping hip syndrome is simply an audible snapping sound produced during motion of the hip. It has both intra- and extra-articular causes.
iliotibial band snapping over the greater trochanter (iliotibial band syndrome - not always audible)
Sneddon syndrome is a type of systemic non-inflammatory vasculopathy characterized by livedo reticularis and progressive and occlusive cerebrovascular thrombosis involving the medium-sized arteries.
livedo reticularis as a skin manifestation
progressive cerebral stroke...
Sotos syndrome it is an autosomal dominant syndrome considered as a form of cerebral gigantism, most characterized by the prenatal and postnatal overgrowth.
There is no ethnic group predominance and has been detected throughout the world. The prevalence is not known but is estimat...
Spigelian-cryptorchidism syndrome is the association of Spigelian hernias and cryptorchidism in children.
It is reported that ~50% (range 28-75%) range of pediatric patients with Spigelian hernias will have ipsilateral cryptorchidism 1,2.
Along with Spigelian hernia and cryptorchi...
Spinal cord injury (SCI) can be traumatic or non-traumatic (i.e. neoplastic/stenosis) but the syndromes associated with spinal cord injury can be seen in all etiologies.
Injury to the spinal cord can be incomplete or complete and depends upon the mechanism of injury. This is important as differ...
Spondylocostal dysostosis (SCDO) is a rare condition characterized by short-trunk dwarfism secondary to developmental anomalies of the vertebrae and ribs. Previously the condition Jarcho-Levin syndrome (also known as spondylothoracic dysostosis) was grouped together with spondylocostal dysostosi...
Spondyloepiphyseal dysplasia is a type of skeletal dysplasia that mainly involves the spine and proximal epiphyseal centers.
short trunk with protruding abdomen
craniovertebral junction stenosis
Stauffer syndrome is paraneoplastic nephrogenic hepatomegaly. It most commonly occurs in the setting of renal cell carcinoma, and is the enlargement the liver without hepatic metastases. It is a cause of cholestasis and cholestatic jaundice.
History and etymology
It is named after Maurice H. ...
Stevens Johnson syndrome (SJS) is an acute inflammatory skin condition.
SJS is on a spectrum of disease with toxic epidermal necrolysis (TEN) at the more severe end. Terminology depending on how much surface area is involved 1,2:
SJS-TEN overlap: 10-30%
Stewart-Treves syndrome refers to an angiosarcoma seen in the setting of lymphoedema 1.
It was classically attributed to lymphoedemas induced by radical mastectomy to treat breast cancer. Nowadays, we know that it can arise in any chronically lymphoedematous region due to any cause2.
Stickler syndrome refers to a group of disorders primarily affecting connective tissue.
Several gene mutations have been idntified dependent on specific sub types which include:
Stickler syndrome type I: COL2A1
Stickler syndrome type II: COL9A1
Stickler syndrome type III: COL11A1
Stiff person syndrome, previously known as stiff man syndrome, was first described in 1956 by Moersch and Woltman of Mayo Clinic 1 and is a very rare neuromuscular disease characterized by:
progressive muscle stiffness of the spine and lower extremities
muscle spasms triggered by external stim...
Straight back syndrome refers to decreased thoracic kyphosis ("flattening") and decreased anteroposterior thoracic diameter, such that there is compression of cardiovascular or bronchial structures.
It should not be confused with flat back syndrome, which refers to decreased lumbar lordosis, o...
Sturge-Weber syndrome, or encephalotrigeminal angiomatosis, is a phakomatosis characterized by facial port wine stains and pial angiomas.
It is part of a wide spectrum of possible phenotypes included in the craniofacial arteriovenous metameric syndrome (CAMS).
Subclavian steal syndrome (SSS) and subclavian steal phenomenon both result from occlusion or severe stenosis of the proximal subclavian artery resulting in retrograde flow in the ipsilateral vertebral artery.
Subclavian steal phenomenon refers to steno-occlusive disease of the pro...
Subependymal hamartomas are seen in patients with tuberous sclerosis. They are located along the ventricles and are mostly asymptomatic. As with other hamartomas, they grow at the same rate as the surrounding tissues.
On imaging, they appear as small intraventricular mass, smaller than 1 cm, an...
Sulcal artery syndrome is a rare cause of spinal cord infarction involving the territory of one of the sulcal arteries, which are penetrating branches of the anterior spinal artery, each vessel supplying either left or right side of the cord, but not both. The result is an incomplete Brown-Séqua...
Superior mesenteric artery (SMA) syndrome, also known as Wilkie syndrome, is a rare acquired vascular compression disorder in which acute angulation of superior mesenteric artery (SMA) results in compression of the third part of the duodenum leading to obstruction.
It should not be confused wit...
Superior orbital fissure syndrome (SOFS) or Rochon–Duvigneaud syndrome is a rare complication of craniofacial trauma with an orbital fracture that extends to the superior orbital fissure that results in injury to the cranial nerves III, IV, V (ophthalmic branch of the trigeminal nerve) and VI as...
Superior semicircular canal dehiscence syndrome (SCDS) is an inner ear abnormality, where a clinical disequilibrium phenomenon is associated with the absence of the bony covering of the superior semicircular canal (SSC).
Notably, this CT finding has also been described in ~10% of individuals wi...
Superior vena cava (SVC) obstruction can occur from extrinsic compression, intrinsic stenosis, or thrombosis. Malignancies are the main cause and are considered an oncologic emergency. Superior vena cava syndrome (SVCS) refers to the clinical syndrome with symptoms that results from this obstruc...
Susac syndrome (SS), also known as SICRET syndrome (small infarctions of cochlear, retinal and encephalic tissue), is a rare syndrome typically affecting young to middle-age women that is clinically characterized by the triad of acute or subacute encephalopathy, bilateral sensorineural hearing l...
Sweet syndrome (acute febrile neutrophilic dermatosis) is characterized by a constellation of clinical symptoms, physical features, and pathologic findings which include:
tender erythematous skin lesions (papules, nodules, and plaques)
a diffuse infiltrate consisting predo...
Swyer-James syndrome (SJS), also known as Swyer-James-MacLeod syndrome and Bret syndrome, is a rare lung condition that manifests as unilateral hemithorax lucency as a result of postinfectious obliterative bronchiolitis.
The condition typically follows a viral respiratory infecti...
A syndrome is a constellation of symptoms and signs that are associated as part of a shared etiology, pathogenesis or disease entity.
Syndrome of inappropriate antidiuretic hormone secretion (SIADH or SIAD) was described in patients with lung cancer who developed hyponatremia associated with continued urinary sodium loss. The result is often dilutional hyponatremia in which the sodium remains normal but total body fluid increa...
Syndrome of the trigone occurs when intracranial tumors that arise in the trigone of the lateral ventricle present with a distinctive constellation of signs and symptoms due to compression of the posterior limb of the internal capsule and the adjacent white matter of the parietal and posterior f...
von Hippel-Lindau disease
Tarsal tunnel syndrome refers to an entrapment neuropathy of the tibial nerve or of its branches within the tarsal tunnel. This condition is analogous to carpal tunnel syndrome.
The most common symptoms are pain and paresthesia in the toes, sole, or heel and the main find...
Taussig-Bing anomaly is a rare congenital heart malformation and is one of the variants of double outlet right ventricle. It consists of transposition of the aorta to the right ventricle and malposition of the pulmonary artery with subpulmonary ventricular septal defect.
History and etymology
Terson syndrome refers to vitreous hemorrhage associated with subarachnoid hemorrhage, however some authors include retinal hemorrhage as well. The syndrome is a poor prognostic marker in patients with subarachnoid hemorrhage.
Terson syndrome has been reported to occur in 13-50% o...
Thanatophoric dysplasia is a lethal skeletal dysplasia. It is the most common lethal skeletal dysplasia followed by osteogenesis imperfecta type II.
The estimated incidence is around 1:25,000-50,000 3.
It results from a mutation coding for the fibroblast gro...
Thoracic outlet syndrome (TOS) refers to a group of clinical syndromes caused by congenital or acquired compression of the brachial plexus or subclavian vessels as they pass through the superior thoracic aperture.
Clinical presentation will depend on the structure compre...
Thrombocytopenia with absent radius (TAR) syndrome is primarily characterized by the following two features:
absent fetal radii (bilaterally) with the presence of both thumbs
The condition is extremely rare with an estimated incidence of 0.4 per 100,000 bi...
Thyrotoxicosis is a hypermetabolic clinical syndrome caused by a pathological excess of circulating free T4 (thyroxine) and/or free T3 (tri-iodothyronine).
Although commonly done, thyrotoxicosis should not be confused with, nor is it synonymous with hyperthyroidism. The latter term...
Top of the basilar syndrome, also known as rostral brainstem infarction, occurs when there is thromboembolic occlusion of the top of the basilar artery. This results in bilateral thalamic ischemia due to occlusion of perforator vessels.
Clinically, top of the basilar synd...
Townes-Brocks syndrome (Renal-Ear-Anal-Radial (REAR) syndrome) is a rare autosomal dominant disease characterized by renal, anal, ear, and thumb abnormalities.
The major manifestations of this syndrome include:
renal: displaced or rotated kidneys, horseshoe kidney, p...
Treacher Collins syndrome, also known as mandibulofacial dysostosis, is an autosomal dominant genetic abnormality and results from bilateral malformations of 1st and 2nd branchial arches.
The incidence is estimated at approximately 1 in 50,000 live births, with 60% of cases being...
Trotter syndrome relates to advanced nasopharyngeal carcinoma and is the constellation of:
unilateral conductive hearing loss due to middle ear effusion
trigeminal neuralgia due to perineural spread
soft palate immobility
Trousseau syndrome (not to be confused with Trousseau sign) represents the association between migratory thrombophlebitis and malignancy; hence one of its other names: cancer-associated thromboembolism.
History and etymology
Armand Trousseau (1801-1867), was a French physician who was the fir...
Turcot syndrome is one of the variations in polyposis syndromes. It is characterized by multiple colonic polyps and an increased risk of colon and primary brain cancers.
Turcot syndrome is a rare disease. Patients typically present in the second decade 3.
Turner syndrome, also known as 45XO or 45X, is the most common of the sex chromosome abnormalities in females.
The incidence is estimated at 1:2000-5000 of live births, although the in utero rate is much higher (1-2% of conceptions) due to a significant proportion of fetuses with...
Twin embolization syndrome (TES) is a rare complication of a monozygotic twin pregnancy following an in utero demise of the co-twin.
It was traditionally thought to result from the passage of thromboplastic material into the circulation of the surviving twin which causes ischemic str...
Twin to twin transfusion syndrome (TTTS) is a potential complication that can occur in a monochorionic twin (either MCDA or MCMA) pregnancy.
This complication can occur in ~10% (range 15-25%) of monochorionic pregnancies giving an estimated prevalence of ~1:2000 of all pregnancie...
Ulnar dimelia or mirror hand syndrome is a rare congenital anomaly of the upper limb characterized by absence of the radial ray (including thumb), duplication of the ulna and duplication of the ulnar halves of the carpals, metacarpals and phalanges 1.
The embryology of mi...
Ulnar styloid impaction syndrome refers to wrist pain due to a long ulnar styloid process impacting upon the triquetral bone.
An unlar styloid >6mm in length is commonly regarded as being long. Impaction results in chondromalacia of the opposing articular surfaces, i.e. the proximal ...
VACTERL is an acronym that describes a non-random constellation of congenital anomalies. It is not a true syndrome as such and is equivalent to the VATER anomaly.
The estimated incidence is 1 in 10,000-40,000 births 3.
The acronym VACTERL derives from:
V: vertebral an...
Valgus extension overload syndrome, also known as pitcher's elbow, refers to a constellation of symptoms and pathologies commonly seen in overhead throwing athletes secondary to high repetitive tensile, shear and compressive forces generated by the overhead throwing motion.
The syndrome may cor...
van der Woude syndrome (VWS) is characterized by the association of congenital lower lip fistulae/pits with cleft lip and/or palate.
It is one of the most common clefting syndromes in humans 1 and affected individuals have a high prevalence of hypodontia.
It carries an aut...
The are numerous vascular syndromes that can occur in the body. There include
Syndromes principally involving the vascular system
celiac artery compression syndrome
hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome)
hypothenar hammer syndrome
VATER (equivalent to VACTERL) is the non-random constellation of a number of congenital anomalies.
V: vertebral anomalies
A: anal atresia
TE: tracheo-oesophageal fistulas
R: radial ray hypoplasia, polydactyly and renal agenesis
The prevalence of at least 3/5 anomalies occurs...
Ventral cord syndrome (also known as anterior cord syndrome) is one of the incomplete cord syndromes and affects the anterior parts of the cord resulting in a pattern of neurological dysfunction dominated by motor paralysis and loss of pain, temperature and autonomic function. Anterior spinal ar...
Vernet syndrome (also known as the jugular foramen syndrome) is a constellation of cranial nerve palsies due to compression from a jugular foramen lesion such as a glomus jugulare tumor or schwannoma. It consists of motor paralysis of:
glossopharyngeal nerve (CN IX)
vagus nerve (CN X)
Vogt-Koyanagi-Harada syndrome is a multisystem disorder characterized by granulomatous panuveitis with exudative retinal detachments that is often associated with neurologic and cutaneous manifestations.
Vogt-Koyanagi-Harada usually affected those of Asian, Middle Eastern, Asian I...