Nijmegen breakage syndrome (NBS) (also known as Seemanova syndrome or Berlin breakage syndrome) is a rare autosomal recessive syndrome of chromosomal instability.
Main clinical features are:
microcephaly present at birth and
progressive with age
dysmorphic facial feat...
Nonsteroidal anti-inflammatory drug (NSAID) exacerbated respiratory disease or previously known as Samter syndrome or aspirin or analgesic-induced asthma refers to the constellation of 1-2:
allergy to aspirin
nasal polyposis / rhinosinusitis
In adults, prevalence can ran...
Noonan syndrome with multiple lentigines, previously known as LEOPARD syndrome (LS), is a rare autosomal dominant RASopathy that has many similarities to Noonan syndrome.
Despite a change in formal name, the 'LEOPARD' acronym is still useful to summarise the clinical feat...
Norrie disease is a rare X-linked inherited cause of congenital bilateral blindness. It can present with a retinal mass (pseudoglioma) and cataracts. It is associated with developmental delay and hearing loss.
Nothnagel syndrome is a rare midbrain stroke syndrome that involves the tectum of the midbrain, including the quadrigeminal plate 1-4.
Classically, the syndrome involves the oculomotor nerve fascicles and superior cerebellar peduncle, leading to ipsilateral CN III palsy a...
Nutcracker syndrome is a vascular compression disorder and refers to the compression of the left renal vein between the superior mesenteric artery (SMA) and aorta. This can lead to renal venous hypertension, resulting in rupture of thin-walled veins into the collecting system with resultant haem...
Occipital horn syndrome is a rare X-linked disorder of copper metabolism resulting in connective tissue abnormalities. The Menkes disease / kinky hair syndrome is the severe form of this disease, with patients rarely surviving past 3 years of age. Occipital horn syndrome (also known as X-linked...
Olecranon bursitis refers to inflammation of the olecranon bursa. The olecranon bursa is a subcutaneous sac that overlies the olecranon process and contains a small amount of fluid to prevent against injury of subcutaneous tissue and skin from the uncovered bony olecranon.
Ophelia syndrome is the association of Hodgkin lymphoma with an autoimmune limbic encephalitis, as a result of anti-metabotropic glutamate receptor 5 antibodies (mGluR5) 1.
Organophosphate poisoning is an important cause of acute neurological dysfunction and respiratory distress.
Organophosphate poisoning is common, often as a result of suicidal ingestion (acute high-level exposure) or occupational exposure to pesticides (chronic low-level exposure) ...
Ortner syndrome, also known as cardiovocal syndrome, is characterised by hoarse voice resulting from left recurrent laryngeal nerve palsy secondary to a cardiovascular disorder.
Left recurrent laryngeal nerve palsy in this condition is due to traction or compression of the nerve betw...
Osteopathia striata with cranial sclerosis (OS-CS) is a clinically separate entity from osteopathia striata (Voorhoeve disease). Bony changes on their own are typically incidental and autosomal dominant, whereas OS-CS is a multisystem, X-linked dominant disorder.
OS-CS is extremel...
Osteoporosis pseudoglioma syndrome is a rare autosomal recessive disease that is characterised by severe osteoporosis and blindness. This disease is frequently mistaken for osteogenesis imperfecta.
This disease is encountered in approximately 1 in 2 million births.
Otopalatodigital syndrome type I is a rare genetic disorder marked by the association of
and a characteristic face (with hypertelorism, broad nasal root, prominent supraorbital ridges, small flat nose and downslanted palpebral fissures).
It is ...
Ovarian vein syndrome is a relatively rare condition where a dilated ovarian vein causes notching, dilatation, or obstruction of the ureter. This is usually secondary to varicoses of the ovarian vein or ovarian vein thrombosis and occurs at the point where the ovarian vein crosses the ureter.
Paget-Schrötter syndrome, alternatively spelled Paget-Schroetter syndrome and also known as effort thrombosis, refers to primary thrombosis of the axillary and/or subclavian vein. It can be thought of as a venous equivalent of thoracic outlet syndrome.
It is associated with forced...
Pancoast syndrome results from involvement of the brachial plexus and sympathetic chain by a Pancoast tumour or, less commonly, from other tumours involving the superior pulmonary sulcus. The syndrome consists of:
C8-T2 radicular pain
The classical syndrome is u...
Pantothenate kinase-associated neurodegeneration (PKAN), previously known as Hallervorden-Spatz syndrome, is an autosomal recessive disorder causing involuntary spasticity and progressive dementia. It is a subset of neurodegeneration with brain iron accumulation (NBIA).
Paradoxical brain herniation, also known as sinking skin flap syndrome (SSFS), is a rare and potentially fatal entity complicating decompressive craniectomy.
Atmospheric pressure exceeding intracranial pressure at the craniectomy results in displacement of the brain across various i...
Paraneoplastic syndromes occur secondary to the indirect effects of a malignancy and occur remotely to the primary malignancy. Symptoms are mediated by cytokines, hormones or immune cross-reactivity. These syndromes can cause a diverse range of symptoms and can affect multiple systems.
Parinaud syndrome, also known as the dorsal midbrain syndrome, is a supranuclear vertical gaze disturbance caused by compression of the tectal plate.
It is characterised by a classic triad of findings:
upward gaze palsy, often manifesting as diplopia
pupillary light-near dissociation (pupils ...
Parkinson-plus syndrome refers to a loose group of neurodegenerative disorders that are characterised by features of Parkinson disease but with other neurological symptoms/signs. They have a poor response to levodopa, and mostly have fairly characteristic neuroimaging features.
Parry-Romberg syndrome (PRS), also known as progressive facial hemiatrophy (PFH), is a rare progressive craniofacial disorder (phakomatosis).
It is classically characterised by a slow progressive degeneration (atrophy) of the soft tissues of half of the face (hemifacial atrophy). This involves ...
Parsonage-Turner syndrome is an acute idiopathic brachial neuritis.
There is male predominance (M:F 2:1 to 11.5:1) 1. Patients from 3 months to 85 years old have been reported, but the majority are between 3rd to 7th decade of life.
The presentation is typi...
Patau syndrome (also known as trisomy 13) is considered the 3rd commonest autosomal trisomy.
This along with Down syndrome (T21) and Edward syndrome (T18) are the only three trisomies to be compatible with extrauterine life. However, few infants live more than a few days.
Pelvic congestion syndrome (some prefer pelvic venous insufficiency 9) is a condition that results from retrograde flow through incompetent valves in ovarian veins. It is a commonly missed and potentially-treatable cause of chronic abdominopelvic pain.
It tends to be more common ...
PELVIS or LUMBAR syndrome is the combination of pelvic haemangiomas with other extracutaneous abnormalities. The syndrome may be incomplete.
external genital malformations
Pendred syndrome is an autosomal recessively inherited disorder characterised by a euthyroid goitre associated with sensorineural hearing loss.
It is considered the most common form of syndromic hearing loss and accounts for upwards of 10% of hereditary deafness.
Pepper syndrome is of interest only (the term is not readily used in day-to-day practice), and refers to primary adrenal neuroblastoma with extensive liver metastases 1. In essence, it refers to stage 4S neuroblastoma (see staging of neuroblastoma).
Peutz-Jeghers syndrome is one of the polyposis syndromes. It has an autosomal dominant inheritance and is characterised by:
multiple hamartomatous polyps, most commonly involving the small intestine (predominantly the ileum), but also colon and stomach; mouth and oesophagus are spared
PHACE syndrome, also known as cutaneous haemangioma–vascular complex syndrome or Pascual-Castroviejo type II syndrome, is a phakomatosis that comprises of:
P: posterior fossa malformations (e.g. Dandy-Walker malformation)
A: arterial anomalies
C: coarctation of the aorta and ...
Phlegmasia cerulea dolens (PCD) is an uncommon complication of deep venous thrombosis, which results from extensive thrombotic occlusion of the major and collateral veins of an extremity (usually the legs).
Left leg is more commonly affected than the right 4.
Pickwickian syndrome, or obesity hypoventilation syndrome (OHS), comprises the triad of obesity (BMI ≥30 kg/m2), daytime hypoventilation (awake hypercapnia and hypoxemia), and sleep-disordered breathing in the absence of alternative explanations (e.g. severe parenchymal lung disease, mechanical ...
Pinch-off syndrome is a spontaneous catheter fracture, which is seen as a complication of subclavian venous catheterisation.
It is a known complication of central venous catheterisation with a much-reduced incidence in current practice and is generally considered to be rare.
Pituitary stalk transection syndrome, also known as pituitary stalk interruption syndrome, is a syndrome characterised by absent or hypoplastic anterior pituitary gland, thin or absent infundibulum, and ectopic posterior pituitary location.
Patients with pituitary stalk transectio...
Plummer-Vinson syndrome, also known as the Paterson-Brown-Kelly syndrome, predisposes to hypopharyngeal squamous cell carcinoma and consists of four features:
oesophageal webs or hypopharyngeal webs
The condition is more common in women.
POEMS syndrome is an acronym for a rare multisystem disorder comprising of a minimum of three of the following features in the setting of a plasma cell dyscrasia:
M: monoclonal gammopathy
S: skin changes (including hyperpigmentation and sk...
Poland-Möbius syndrome, is the combination of Möbius syndrome and Poland syndrome, which although very rare, has been well described 1.
Sir Alfred Poland (1822-1872): English surgeon 2
Paul Julius Möbius (1853-1907): German neurologist 3
Poland syndrome refers to a congenital unilateral absence of the pectoralis major and minor muscles and is a recognised cause of unilateral hyperlucent hemithorax.
Poland syndrome is usually sporadic, although rare familial cases have been described 1. It is rare, with an estimat...
Polycystic ovarian syndrome (PCOS), recently referred also as hyperandrogenic anovulation, is a chronic anovulation syndrome associated with androgen excess.
The diagnosis is made on the combined clinical, biochemical and sonographic grounds. The revised 2003 ASRM/ESHRE Rotterdam consensus cri...
Polydactyly (less commonly called hyperdactyly) refers to the situation where there are more than the usual number of digits (five) in a hand or foot. It can be broadly classified as:
pre-axial polydactyly: extra digit(s) towards the thumb/hallux (radially)
post-axial polydactyly: extra digit(...
Popliteal artery entrapment syndrome (PAES) refers to symptomatic compression or occlusion of the popliteal artery due to a developmentally abnormal positioning of the popliteal artery in relation to its surrounding structures such as with the medial head of gastrocnemius (MHG) or less commonly ...
Post-ablation syndrome occurs from 24 to 48 hours following ablation, and lasts no longer than 10 days1. It is believed to occur following cytokine release and tumor necrosis, causing patient fever and flu-like symptoms.
If symptoms persist following 10 days after the procedure, alternate diagn...
Post-axial polydactyly refers to polydactyly where the additional digit is on the ulnar margin of the hand, or lateral to the 5th toe.
Post-axial polydactyly is more common than pre-axial polydactyly, with an estimated incidence of 1 in 3000.
Post-embolisation syndrome (PES) is one of the commonest side effects of transarterial embolisation and chemoembolisation. It comprises of a constellation of fever, nausea/vomiting, and pain. It usually occurs within the first 72 hours after embolisation (liver lesion or uterine fibroids) and th...
Posterior choroidal artery occlusion uncommonly presents as an isolated stroke syndrome. It usually coexists with posterior cerebral artery and often superior cerebellar artery involvement.
When seen in isolation damage is characteristically limited to the:
lateral geniculate body
Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic state that occurs secondary to the inability of the posterior circulation to autoregulate in response to acute changes in blood pressure. Hyperperfusion with resultant disruption of the blood brain barrier results in vasogenic o...
Posterior spinal artery syndrome is a rare syndrome associated occlusion of the posterior spinal artery and results in a unilateral dorsal cord syndrome (since the posterior arteries are paired) 3.
The syndrome is clinically characterised by isolated loss of proprioception and vibratory sensat...
Post-pneumonectomy syndrome is delayed complication of pneumonectomy characterised by respiratory compromise caused by severe mediastinal shift and counterclockwise rotation of the heart and great vessels.
Rare delayed complication of pneumonectomy, which more commonly involves th...
Post thrombotic syndrome (PTS) is a syndrome of chronic venous insufficiency following deep vein thrombosis (DVT) due to valvular incompetence, which results in chronic reflux and chronic venous hypertension.
PTS is a common complication following extensive DVT of the limbs. Up to...
PPP syndrome is the extremely rare association of pancreatitis, panniculitis, and polyarthritis.
Most commonly affects middle-aged male patients with a history of heavy alcohol use 1,2.
In the majority of cases, abdominal symptoms are mild or absent, makin...
Pre-axial polydactyly refers to polydactyly where the additional digit is towards the first digit of the hand (radial side) or foot (medially).
Pre-axial polydactyly is less common than post-axial polydactyly, with an estimated incidence of 1 in 7000.
Primary progressive aphasia was first described in 1982 and is the umbrella term for the language-variant frontotemporal dementias associated with frontotemporal lobar degeneration (FTLD) 3.
It is an insidious disorder characterised by gradual impairment of speech and lan...
Progeria is a term used for any syndrome in which a person is prematurely aged, however, it most commonly refers to Hutchinson-Gilford progeria syndrome (HGPS).
Although the primary clinical manifestations of progeria include short stature and skin changes, the disease is...
Pronator teres syndrome (also called pronator syndrome) is one of three common median nerve entrapment syndromes; the other two being anterior interosseous nerve syndrome and the far more common carpal tunnel syndrome. Signs and symptoms result from compression of the median nerve in the upper f...
Proteus syndrome is a rare congenital, multisystemic, hamartomatous condition characterised by asymmetrical overgrowth of almost any part of the body and a broad spectrum of manifestations. It can affect tissue from any germinal layer. It is suspected to be a genetic condition, but a particular ...
Pseudoxanthoma elasticum (PXE), also known as Grönblad–Strandberg syndrome, is a systemic condition characterised by the degeneration of elastic fibres. It has multiorgan manifestations.
Its prevalence is estimated to be around 1 in 25,000 9.
Patients may ...
PTEN (phosphatase and tensin homolog) gene mutation is associated with a few conditions known as PTEN-related diseases, with relatively similar clinical and radiological manifestations. They include:
Those not f...
Quadrangular space syndrome also known as quadrilateral space syndrome is an uncommon diagnosis mainly because of lack of literature on the subject and possible misdiagnosis.
Quadrangular space syndrome is present on ~1% of shoulder MRIs 6.
Radial tunnel syndrome is an entity that refers to entrapment of the radial nerve in the forearm, as it occurs in the supinator syndrome. Some authors believe this is an early form of the posterior interosseous nerve syndrome 5.
The syndrome is characterized by pain along...
Radiologically isolated syndrome (RIS) is defined by MRI findings suggestive of multiple sclerosis (MS) in asymptomatic ("clinically silent") patients. Radiological progression usually occurs in approximately 66% of patients with RIS, while ~ 33% per 5 year period will subsequently develop neuro...
Raghib syndrome is a rare developmental complex. It consists of:
persistence of the left superior vena cava
coronary sinus ostial atresia
atrial septal defect
It has also been associated with other congenital malformations including ventricular septal defects, enlargement of the tricuspid an...
Raine syndrome, also known as lethal osteosclerotic bone dysplasia, is a very rare genetic disorder. Infants with this syndrome present with numerous characteristic craniofacial features as well as cerebral calcifications. Many individuals with this disorder are stillborn or die as neonates 4.
Ramsay Hunt syndrome (RMS), also known as herpes zoster oticus, is essentially shingles of the facial nerve. Latent infection is present in the geniculate ganglion with painful vesicles showing in the external acoustic meatus, tympanic membrane and pinna associated with facial palsy. There may b...
Raymond syndrome is a posterior circulatory stroke syndrome due to a lesion in the ventral medial mid-pons. It is an extremely rare condition, with only a handful of cases described in the literature.
Clinically, 2 subtypes have been reported 1:
abducens nerve ...
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...
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)
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...
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 aetiologies, but is most often due to large osteophytes, atla...
Rubinstein-Taybi syndrome (RTS) is a very rare genetic multi-system disorder primarily characterised 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 characterised 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 paediatric pop...
Schimmelpenning syndrome is a rare and variable congenital multisystem condition characterised by extensive linear naevi sebacei and abnormalities in different neuroectodermal organ systems.
Classical triad including sebaceous nevi, seizures, and intellectual disability....
Sclerosing encapsulating peritonitis is a rare benign cause of acute or subacute small bowel obstruction. It is characterised by total or partial encasement of the small bowel within a thick fibrocollagenous membrane.
The condition was originally termed abdominal cocoon. It has als...
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 characterised by many features including
intrauterine growth restriction (IUGR)
Segmental arterial mediolysis (SAM) is an increasingly recognised vascular disease of the middle-aged and elderly and a leading cause of spontanoeus intra-abdominal haemorrhage. It is characterised by fusiform aneurysms, stenoses, dissections and occlusions within splanchnic arterial branches. I...
Serrated polyposis syndrome (SPS), also called hyperplastic polyposis syndrome, is characterised by the presence of multiple serrated polyps or a mixture of serrated and hyperplastic polyps, with the exact number required for diagnosis dependent on location and family history.
SPS has an hetero...
Sézary syndrome (SS) is a type of cutaneous T-cell lymphoma. It is sometimes considered an advanced and leukaemic form of cutaneous T-cell lymphoma (CTCL).
It is clinically characterised by an extensive erythematous rash covering most of the body as well as the presence o...
Sheehan syndrome is a rare cause of pituitary apoplexy and hypopituitarism.
It only occurs in postpartum females who experience large volume haemorrhage and hypovolaemic shock, either during delivery or afterwards.
pituitary failure 1
may be silent and present with dela...
Shone syndrome, also known as Shone complex, is a rare syndrome characterised 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 characterised by 1 :
exocrine pancreatic insufficiency
bone marrow hypoplasia (cyclic neutropenia)
Patients with Shwachman-...