Complex regional pain syndrome (CRPS), also known as Sudeck atrophy, is a condition which can affect the extremities in a wide clinical spectrum.
Two types of CRPS have been described 8:
type 1: no underlying single nerve lesion (formerly known as reflex sympathetic dystrophy)
Congenital high airways obstruction syndrome (CHAOS) refers to a rare, often lethal, congenital laryngotracheal condition and is primarily characterized by obstruction to the fetal upper airway.
CHAOS can be of three possible types 2:
complete laryngeal atresia without an esophageal...
Congenital pulmonary venolobar syndrome is a condition comprised of a rare group of cardiac and pulmonary congenital abnormalities occurring variably in combination. The abnormalities include:
anomalous pulmonary venous drainage
particularly scimitar syndrome with hypogenic right lung
Conn syndrome, also known as primary hyperaldosteronism, is a condition of excess of aldosterone production and occurs secondary to adrenal cortical adenoma, bilateral adrenal hyperplasia, or rarely, adrenal carcinoma. Differentiation between the causes is required to avoid unnecessary surgery. ...
Conus medullaris syndrome is caused by an injury or insult to the conus medullaris and lumbar nerve roots. It is a clinical subset of spinal cord injury syndromes. Injuries at the level of T12 to L2 vertebrae are most likely to result in conus medullaris syndrome.
Cortical blindness is a condition resulting from lesions in the primary visual cortex (V1) characterized by visual impairment but with an intact anterior visual pathway (normal pupillary reflexes and fundal appearance).
The degree of visual impairment is related to the extent...
Cowden syndrome, also known as multiple hamartoma syndrome, is characterized by multiple hamartomas throughout the body and increased risk of several cancers.
Type 2 segmental Cowden syndrome is the association of Cowden syndrome with a Cowden naevus, when it is considered a type o...
CREST syndrome (a.k.a. limited systemic sclerosis or limited scleroderma) is a variant of progressive systemic sclerosis (PSS) and stands for
C - Calcinosis
R - Raynaud phenomenon
E - Esophageal dysmotility
S - Sclerodactyly
T - Telangiectasia
Cronkhite–Canada syndrome is a type of non-hereditary hamartomatous polyposis syndrome characterized by rash, alopecia, and watery diarrhea.
There is a recognised male predilection. Patients typically are middle age, in their 60th 1.
Patients typically pres...
Crouzon syndrome is rare disorder characterized by premature craniosynostoses.
abnormal calvarial shape: in severe case can give a "cloverleaf skull"
shallow orbits with exopthalmos
mid facial hypoplasia
It carries an autosomal dominant ...
Cubital tunnel syndrome is a type of ulnar nerve compression neuropathy due to pathological compression of the ulnar nerve along its course within the cubital tunnel.
Compression of the ulnar nerve at the elbow is the second most common peripheral neuropathy of the upper extremity...
Cuboid syndrome is a cause of lateral midoot pain, believed to result from abnormal articulation of the cuboid with the calcaneus (calcaneocuboid joint).
Cuboid syndrome presents with lateral foot pain and swelling, often diffuse and similar to an ankle (ligament) sprain ...
Currarino-Silverman syndrome, also known as pectus carinatum type 2 deformity, is a rare disorder in which the patient has a high carinate chest deformity due to a premature fusion of the manubriosternal joint and sternal ossification centers. Congenital heart diseases have been described in mor...
The Currarino syndrome is a complex condition variably comprised of characteristic congenital anomalies of the sacrum, anorectum and presacral soft tissues. It is also known as the Currarino triad or ASP triad, however, not all three features are always present 6.
anorectal malformation or con...
Cyriax syndrome, also known as slipping rib syndrome, occurs when hypermobility of the rib cartilage of the lower ribs slips and moves, leading to pain in lower chest or upper abdomen 1.
This condition may occur at any age, but is reportedly more common in middle-aged adults, and ...
Cystinosis, also known as Abderhalden Kaufmann Lignac syndrome, is the most common hereditary cause of renal Fanconi syndrome. Cystinosis is a form of lysosomal storage disease.
It has a reported incidence of 1:192,000 1. Cystinosis is typically diagnosed in infancy.
Dandy-Walker variant (DWv) is a less severe posterior fossa anomaly than the classic Dandy-Walker malformation (DWM) and is considered being on the lesser end of the disease spectrum in the Dandy-Walker continuum.
This term was created to include those malformations that do not mee...
The distal intersection syndrome relates to tenosynovitis of the extensor pollicis longus (EPL) tendon (3rd extensor compartment), where it crosses the extensor carpi radialis longus (ECRL) and brevis (ECRB) tendons (2nd extensor compartment) 1. It is distinct from intersection syndrome which oc...
Doege-Potter syndrome is a non-islet cell tumor hypoglycemia, secondary to a solitary fibrous tumor (SFT). It is rare, and more associated with malignant SFTs.
Dorsal brainstem syndrome is a rare subset of hypoxic ischemic encephalopathy in neonates limited to the isolated involvement of the brainstem with sparing of the supratentorial brain. Due to its subtle imaging features it is often undiagnosed.
Injuries involving the tegm...
Down syndrome (or trisomy 21) is the most common trisomy and also the commonest chromosomal disorder. It is a major cause of intellectual disability, and also has numerous multi-system manifestations.
According to the world health organization (WHO), the approximate worldwide inci...
Drash syndrome, also known as the Denys-Drash syndrome, is associated with an abnormal WT1 gene (Wilms tumor gene) and consists of:
Dravet syndrome, previously known as severe myoclonic epilepsy of infancy (SMEI), is a rare form of epilepsy usually presenting in the first 1-2 years of life.
The typical presentation occurs during the first six months to one year of life as tonic-clonic seizures in a fe...
Dressler syndrome (DS) is a delayed immune-mediated or secondary pericarditis developing weeks to months after a myocardial infarction (MI).
Dressler syndrome is not to be confused with pericarditis epistenocardica (which is seen earlier in the post-MI period) and is considered a r...
Duane radial ray syndrome (DRRS) (also known as the Okihiro syndrome) is a rare an autosomal dominant condition characterized by radial ray defects and a Duane anomaly (a form of strabismus with horizontal gaze palsy).
Dyke-Davidoff-Masson syndrome (DDMS) is a condition characterized by hemicerebral atrophy/hypoplasia secondary to brain insult usually in fetal or early childhood period and is accompanied by ipsilateral compensatory osseous hypertrophy and contralateral hemiparesis.
It is characterized by:
Dysplasia epiphysealis hemimelica (DEH), also known as Trevor disease, is an extremely rare, non-hereditary disease that is characterized by osteochondromas arising from the epiphyses.
The incidence is estimated at ~1:1,000,000 3. There is a recognised male predilection (M:F = 3:1...
Ectrodactyly-ectrodermal dysplasia-clefting (EEC) syndrome is a rare genetic syndrome that has high clinical variability but typically comprises of the triad of
ectrodactyly +/- syndactyly 1 +/- polydactyly 5
facial clefts: cleft lip and/or palate
Edwards syndrome, also known as trisomy 18, along with Down syndrome (trisomy 21) and Patau syndrome (trisomy 13), make up the only three trisomies to be compatible with extrauterine life in non-mosaic forms, albeit in the case of Edward syndrome only for a week or so.
Ehlers-Danlos syndrome comprises a heterogeneous group of collagen disorders (hereditary connective tissue disease).
There is a recognized male predominance.
Clinically manifests by skin hyperelasticity and fragility, joint hypermobility and blood vessel fr...
Elbow synovial fold syndrome refers to a condition where patients experience a cluster of symptoms due to the presence of synovial folds (also known as synovial fringe or plicae).
It tends to be more common in athletic young adults. It is associated with certain sporting activitie...
Encapsulating peritoneal sclerosis is a rare benign cause of acute or subacute small bowel obstruction. It is characterized by total or partial encasement of the small bowel within a thick fibrocollagenous membrane.
The condition was originally termed abdominal cocoon. The conditio...
Eosinophilic granulomatosis with polyangiitis (EGPA), previously known as the Churg-Strauss syndrome (CSS), refers to a small to medium vessel necrotizing pulmonary vasculitis. It is also classified under the spectrum of eosinophilic lung disease and as a type of pulmonary angiitis and granuloma...
Epidermal nevus syndrome (ENS), also known as Solomon's syndrome or Feuerstein and Mims syndrome, represent a group of distinct disorders related to the presence of epidermal nevi and extracutaneous anomalies. It is a syndrome linked to mosaicism, with many of them occurring exclusively sporadic...
Facial colliculus syndrome refers to a constellation of neurological signs due to a lesion at the facial colliculus, involving:
abducens nerve (CN VI) nucleus
facial nerve (CN VII) fibers at the genu
medial longitudinal fasciculus
lower motor neuron facial nerve palsy ...
Fahr syndrome, also known as bilateral striatopallidodentate calcinosis, is characterized by abnormal vascular calcium deposition, particularly in the basal ganglia, cerebellar dentate nuclei, and white matter, with subsequent atrophy.
It can be either primary (usually autosomal dominant) or se...
Failed back syndrome refers to persistent leg and/or lumbar back pain after a surgical procedure. The pathophysiology of this syndrome is complex, as often the operation was technically successful.
Other names for failed back syndrome include failed back surgery syndrome, post-lam...
Familial adenomatous polyposis syndrome (FAPS) is characterized by the presence of hundreds of adenomatous polyps in the colon. It is the most common of the polyposis syndromes.
Familial polyposis coli, attenuated familial adenomatous polyposis and Gardner syndrome are all variants...
Familial multiple cavernous malformation syndrome(s) are uncommon, accounting for only a minority of cavernous malformations.
It has been more frequently reported in patients of Hispanic descent 1.
The presentation is most commonly with seizures (38-55%) 1 ...
Familial multiple lipomatosis (FML) is a hereditary syndrome of multiple encapsulated lipomas which are found on the trunk and extremities, with relative sparing of the head and shoulders.
It is clinically distinct from the similarly named multiple symmetric lipomatosis with which...
Fatco syndrome is a syndrome consisting of
tibial campomelia and
It is a syndrome of unknown genetic basis and inheritance with variable expressivity and penetrance.
Fuhrmann syndrome and Al-Awadi syndrome are said to be similar to FA...
Fat embolism syndrome (FES) is a rare clinical condition caused by circulating fat emboli leading to a multisystemic dysfunction. The classical clinical triad consists of:
It occurs in ~2.5% (range 0.5-4%) of tho...
Febrile infection-related epilepsy syndrome (FIRES) is a severe postinfectious neurological disorder that presents with status epilepticus in a previously normal child (or less commonly adult) after a febrile illness.
FIRES has received several names in the literature:
Femoral facial syndrome, also known as femoral hypoplasia-unusual facies syndrome, is a rare congenital syndrome characterized by varying degrees of femoral hypoplasia and facial dysmorphism 1.
Femoral facial syndrome can cause varying degrees of femoral malformation rang...
The fetal head sparing theory is one that underpins asymmetrical intra-uterine growth restriction, where the difference between normal head circumference and decreased abdominal circumference is attributed to the fetus's ability to preferentially supply the cerebral, coronary, adrenal and spleni...
Fitz-Hugh-Curtis syndrome (FHCS) refers to the development of a perihepatitis in association with pelvic inflammatory disease (PID).
The prevalence in adults with mild to moderate PID (gonorrhoic) may approximate 4% 10. The prevalence may be higher in genital tuberculosis 12. It ...
Flat back syndrome (FBS) refers to the decrease or absence of the normal lumbar lordosis resulting primarily in chronic lumbar pain.
Flat back syndrome is a different condition from straight back syndrome and the two should not be confused or conflated.
Focal dermal hypoplasia syndrome is also known as Goltz syndrome, and is named confusingly similar to Gorlin-Goltz syndrome.
A rare disorder that follows X-linked dominant inheritance pattern. More commonly seen in males than female. Worldwide only 200-300 cases have been reported....
Folliculin gene-associated syndrome (FLCN-S) or Birt-Hogg-Dubé (BHD) syndrome is a genetic multisystemic disease mainly characterized by:
multiple lung cysts and secondary spontaneous pneumothoraces
multiple bilateral renal tumors (particularly chromophobe renal cell cancer and oncocytoma)
Foster Kennedy syndrome describes the clinical syndrome of unilateral optic atrophy with contralateral papilloedema caused by an ipsilateral compressive mass lesion.
The syndrome consists of two cardinal features 1,2:
ipsilateral optic nerve atrophy presenting with centr...
Fowler syndrome, also known as proliferative vasculopathy and hydranencephaly-hydrocephaly syndrome (PVHH), is a rare inherited condition.
Not to be confused with Fowler syndrome of urinary retention, a condition caused by primary failure of urethral sphincter relaxation resulting ...
Fraser syndrome is an extremely rare congenital syndromic anomaly.
The estimated incidence is at around 0.04:10,000 live-born infants and 1:10,000 stillbirths.
The syndromic spectrum can comprises of:
syndactyly: often cutaneous
Freeman Sheldon syndrome (FSS), also known as distal arthrogryposis type IIa, is a congenital condition where multiple joint contractures are a key feature. Affected individuals are known to have a characteristic facial expression resembling that of a whistling face and hence the syndrome is als...
Frontonasal dysplasia, also known as median cleft face syndrome, is a rare disorder characterized by midline defects involving the face, head, and central nervous system.
Frontonasal dysplasia is considered to be a very rare condition, with approximately 100 cases having been repo...
The functional gastrointestinal disorders (FGIDs) are a set of conditions characterized by their chronic GI manifestations, in the absence of structural abnormality of the gut. These conditions are common and may be disabling in nature. The understanding of their pathogenesis is incomplete, comp...
Gasperini syndrome is a rare pontine stroke syndrome that involves the caudal pons tegmentum.
Classically, the syndrome presents with 1-3:
involvement of the CN V nucleus: ipsilateral facial sensory loss
involvement of the CN VI nucleus: ipsilateral impaired eye abducti...
GATA2 deficiency is a germ-line disease expressed as a wide spectrum of phenotypes, including monocytopenia, myelodysplasia, myeloid leukaemias, and lymphoedema. It is a rare cause of pulmonary alveolar proteinosis.
GATA2 deficiency has considerably variable clinical mani...
Gerstmann-Straussler-Scheinker disease is a very rare type of human transmissible spongiform encephalopathy. It manifests with dementia and/or ataxia and is due to a mutation in the prion protein (PRNP) gene, which is inherited in an autosomal dominant pattern.
History and etymology
It is nam...
Gerstmann syndrome, also known as angular gyrus syndrome, is a dominant hemisphere stroke syndrome consisting of four components:
agraphia or dysgraphia
acalculia or dyscalculia
Pure Gerstmann syndrome is said to be without aphasia.
History and ety...
Gillespie syndrome is a rare genetic condition presenting as a mydriasis, secondary to an omnipresent partial aniridia. The abnormal iris is bilateral, with a highly-specific scalloped inner margin, due to hypoplasia of the central constrictor pupillae fibers. Associated features include an unch...
Glycogen storage disease (GSD) refers to a number of syndromes which are characterized by a defect in synthesis, metabolism or storage of glycogen.
There are many types of GSD:
type I: von Gierke disease
type II: Pompe disease
type III: Cori or Forbes disease
type IV: Andersen di...
Glycogen storage disease type I (GSD-I), also known as von Gierke disease, is a type of glycogen storage disease where there is excess deposition of glycogen primarily in the liver, but also in the kidney and small bowel.
It occurs approximately one in every 100,000 live births 2,...
Goldenhar syndrome (also known as oculo-auriculo-vertebral spectrum (OAVS), Goldenhar-Gorlin syndrome or facio-auriculo-vertebral dysplasia) is a complex congenital anomaly characterized by abnormalities of the ears, eyes and vertebrae.
The estimated incidence is at 1 in 3000-500...
Gomez-Lopez-Hernandez syndrome, also known as cerebellotrigeminal-dermal dysplasia, is a rare phakomatosis characterized by rhombencephalosynapsis, parietal-occipital scalp alopecia, brachycephaly, facial malformations and trigeminal anesthesia.
History and etymology
It is named after Manuel ...
Goodman syndrome is a type of acrocephalopolysyndactyly (often considered type IV). It is an extremely rare genetic disorder characterized by marked malformations of the head and face, abnormalities of the hands and feet, and congenital heart disease. The syndrome is inherited as an autosomal re...
Goodpasture syndrome, also referred as antiglomerular basement membrane (anti-GBM) antibody disease, is an autoimmune disease characterized by damage to the alveolar and renal glomerular basement membranes by a cytotoxic antibody. It is a type of pulmonary-renal syndrome.
Goodpasture syndrome i...
Good syndrome is a rare paraneoplastic syndrome in which a thymoma causes hypogammaglobulinemia and humoral immunodeficiency. It has been estimated to occur in 0.2%–2% of thymomas 2.
low to absent B-cells
T-cell mediated defects
CD4 T-cell lymphopenia
inverted CD4/CD8+ T-cell ratio
Gradenigo syndrome consists of the triad of:
abducens nerve palsy, secondary to involvement of the nerve as it passes through Dorello canal
retro-orbital pain, or pain in the cutaneous distribution of the frontal and maxillary divisions of the trigeminal nerve, due to extensi...
The Greig cephalopolysyndactyly syndrome (GCPS) is a rare pleiotropic, multiple congenital anomaly syndrome.
It is primarily characterized by:
preaxial polydactyly (most common 2) or
mixed pre- and postaxial polydactyly
true ocular hypertelorism
Grisel syndrome is a rare cause of torticollis that involves subluxation of atlanto-axial joint from inflammatory ligamentous laxity following an infectious process in the head and neck, usually a retropharyngeal abscess.
It usually occurs in infants or young children.
Guillain-Barré syndrome (GBS) is defined as a heterogeneous group of autoimmune polyradiculopathies, involving sensory, motor and autonomic nerves. It is the most common cause of rapidly progressive flaccid paralysis. It is believed to be one of a number of related conditions, sharing a similar ...
Gullo syndrome, also known as benign pancreatic hyperenzymaemia, is characterized by the abnormal elevation of the serum levels of most or all of the pancreatic enzymes without any evidence of underlying pancreatic pathology. All other laboratory assays and imaging studies are unremarkable.
A hemoglobinopathy is a genetic disorder which alters the structure of hemoglobin 1. The result is reduced oxygen-carrying capacity of the blood to the tissues.
Types of hemoglobinopathies include the following:
sickle cell disease (Hb S)
sickle cell trait (HB AS)
Hemolytic uremic syndrome (HUS) is a multisystem thrombotic microangiopathic disease characterized by the triad of renal failure, hemolytic anemia and thrombocytopenia. It is the most common cause of renal failure in infancy and childhood requiring dialysis.
There are two forms of this syndrom...
Haemophagocytic lymphohistiocytosis (HLH), also known as macrophage activation syndrome when occurring in the setting of a rheumatologic disorder, is a non-malignant but often-fatal disorder of immune dysregulation affecting multiple organs.
It typically affects infants and young ...
Haglund syndrome refers to the triad (Haglund triad) of:
insertional Achilles tendinopathy
Haglund deformity (i.e. posterosuperior calcaneal exostosis)
This results in pain at the back of the heel. It is associated with calcaneal spurs, and the wearing of high heels (...
Hajdu-Cheney syndrome is a very rare connective tissue disorder with only 50 cases reported in the literature 2.
It is mostly diagnosed in adulthood or adolescence with the presence of a positive family history. There has been no link between severity of disease and age o...
Hamatolunate impingement is an uncommon cause of ulnar-sided wrist pain. The condition occurs most commonly in wrists where there is type II lunate morphology (existence of a medial facet on the distal lunate for articulation with the hamate). Repeated impaction of the opposing articular surface...
Hamman syndrome, also known as Macklin syndrome, refers to spontaneous pneumomediastinum along with subcutaneous emphysema.
It is a rare entity most often encountered in young adults. It is a known entity peri- and postpartum 3.
The condition is most common...
Hand-foot syndrome, also known as palmar-plantar erythrodysaesthesia or Burgdorf reaction, is a benign, aseptic, self-limiting complication of many chemotherapeutic agents characterized by a widespread erythema, edema and ulceration of the hands and feet.
Heerfordt syndrome, also known as Heerfordt-Waldenström syndrome or uveoparotid fever, is a variant of sarcoidosis, comprising of:
ocular involvement (anterior uveitis)
The exact prevalence is unknown, as only isolated case reports exist....
The Heiner syndrome is a rare form of primary pulmonary hemosiderosis associated with an allergy to cow's milk. The syndrome includes:
rectal blood loss with hypochromic microcytic anemia
pulmonary infiltrates (often recurrent)
HELLP syndrome is a pregnancy-related condition and is an abbreviation for:
elevated liver enzymes and
It is considered a severe and life-threatening form of pre-eclampsia although it can occur without co-existing pre-eclampsia.
The estimated inciden...
Hemiconvulsion-hemiplegia epilepsy syndrome (HHE) is a clinical syndrome of infancy or early childhood that is associated with seizures, cerebral hemiatrophy and transient or permanent epilepsy.
It refers to the characteristic holohemispheric global atrophy of one hemisphere, that is independen...
Hemifacial microsomia (HFM) is the second most common congenital facial anomaly after cleft lip/palate. The condition may vary from mild to severe. Goldenhar syndrome has been described as a variant of HFM, in which vertebral anomalies and epibulbar dermoids were present.
HFM is al...
Hemihyperplasia, also known as hemihypertrophy, is asymmetry in size between the right and left of the body, more than can be attributed to normal variation.
Hemihyperplasia is more scientifically correct than hemihypertrophy as the cells are hyperplastic rather than hypertrophied ...
Hemimedullary syndrome, also known as Reinhold syndrome, occurs as a result of the occlusion of the ipsilateral vertebral artery proximal to the posterior inferior cerebellar artery and its anterior spinal artery branches 1-3. This situation causes lateral medullary infarct and medial medullary ...
Hepatopulmonary syndrome (HPS) refers to the combination of
hepatic dysfunction (cirrhosis)
hypoxemia (alveolar-arterial O2 gradient of >15 mmHg; >20 mmHg in >64 years old patients)
peripheral pulmonary arterial dilatation (due to right to left micro-shunts)
It is estimated to ...
Hereditary angiopathy with nephropathy, aneurysms, and muscle cramps (HANAC) syndrome is an autosomal dominant monogenic COL4A1-related disorder.
The exact prevalence is unknown.
The cardinal features of HANAC syndrome are helpfully described in the name of...
Hereditary breast and ovarian cancer (HBOC) syndrome is caused by a mutation to either BRCA1 or BRCA2 genes. These patients have an increased risk of breast cancer, ovarian cancer, pancreatic cancer and prostate cancer. However, these gene mutations are not the only cause of hereditary breast ca...
Hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is a rare inherited disorder characterized by abnormal blood vessel formation in the skin, mucous membranes, and organs including the lungs, liver, and central nervous system.
Hereditary multiple exostoses, also known as diaphyseal aclasis or osteochondromatosis is an autosomal dominant condition, characterized by the development of multiple osteochondromas.
Hereditary multiple exostoses demonstrate an autosomal dominant inheritance pattern, with incomp...
Hereditary non-polyposis colorectal cancer (HNPCC), also known as Lynch syndrome, is an inherited condition which predisposes to a host of malignancies, including colorectal carcinoma. It is considered the most frequent form of hereditary colorectal cancer. Diagnosis requires evaluation using cl...