Syndromes Glossary
Acanthosis nigricans
Skin disorder characterized by dark, thick, velvety skin in body folds and creases; can occur in healthy
people or associated with medical problems, including obesity, glucose-resistance, diabetes,
lymphoma, cancers of the GI or GU tracts, or those on hormones (i.e., growth hormone or oral
contraceptives).
Achondroplasia
autosomal-dominant, often new mutation; characterized by short limbs, short stature,
megalocephaly, small foramen magnum (low risk of cord compression), caudal narrowing of spinal
canal, low nasal bridge, prominent forehead, mild hypotonia, normal intelligence, relative glucose
intolerance.
Adie syndrome
Tonic pupil, usually characterized by mydriasis (dilated pupil) with little or no reaction to light, but
may manifest as miotic, poorly reactive pupils; pupil may react to accommodation; associated with
hyporeflexia.
Alagille syndrome (arterio-hepatic dysplasia)
autosomal-dominant; characterized by paucity or absence of intrahepatic bile ducts with progressive
destruction of bile ducts, cholestasis, peripheral pulmonic stenosis, peculiar facies (broad forehead,
deep-set eyes that are widely spaced and underdeveloped, a small, pointed mandible), cardiac
lesions, vertebral arch defects, and changes in the renal tubules and interstitium.
Alport syndrome
Defective type IV collagen, most often X-linked, but with autosomal-dominant and -recessive forms;
characterized by progressive nephritis to renal failure and neurosensory deafness; usually presents
in infancy with hematuria, with proteinuria and hearing loss being later findings.
Asperger syndrome
developmental disorder on the higher-functioning end of the autism spectrum; patients are often
viewed as brilliant, eccentric, and physically awkward, fail to develop relationships with peers, have
repetitive and stereotyped behaviours, usually with hand movements.
Ataxia-telangiectasia syndrome (Louis-Bar syndrome)
autosomal-recessive; characterized by progressive ataxia, degenerative central nervous system
function, telangiectasia, lymphopenia, immune deficit (low to absent IgA and IgE), growth deficiency,
and mental deficits.
Bartter syndrome
1
hypertrophy of the juxtaglomerular apparatus; characterized by hypokalemic alkalosis,
hypochloremia, and hyperaldosteronism; patients have normal blood pressure but the renin level is
elevated; may lead to mental retardation and small stature.
Behçet syndrome
unknown cause; vasculitis of large and small vessels; involves relapsing iridocyclitis and recurrent
oral and genital ulcerations, white matter changes, aseptic meningitis, pulmonary aneurysm,
arthritis, and arthralgias.
Blind loop syndrome
Stasis of small intestine, usually secondary to incomplete bowel obstruction or a problem of
intestinal motility; can occur following GI surgery or from inflammatory bowel disease or
scleroderma.
Bronchiolitis obliterans
Characterized by obstruction of bronchioles by granulation tissue; begins with necrotizing
pneumonia secondary to viral infection (e.g., adenovirus, influenza, and measles), tuberculosis (TB),
or inhalation of fumes, talcum powder, or zinc.
Cat-eye syndrome
Duplication of segment of chromosome 22; characterized by coloboma of iris, down-slanting
palpebral fissures, anal atresia, cardiac defects, renal agenesis; mild mental deficiency.
Charcot-Marie-Tooth disease (hereditary motor and sensory neuropathy (HMSN) or peroneal
muscular atrophy)
Various inheritance patterns; most common cause of chronic peripheral neuropathy; characterized
by foot drop, high-arch foot; patients may have stocking-glove sensory loss.
Chédiak-Higashi syndrome
Autosomal-recessive; characterized by partial oculocutaneous albinism, increased susceptibility to
infection, lack of natural killer cells, and large, lysosome like granules in many tissues; patients have
splenomegaly, hypersplenism, hepatomegaly, lymphadenopathy, nystagmus, photophobia, and
peripheral neuropathy.
Cri du chat syndrome (5p deletion syndrome)
usually sporadic; characterized by catlike cry in infancy, microcephaly, downward palpebral fissures,
low birth weight, growth retardation, mental deficiency, hypotonia, round face, hypertelorism,
epicanthal folds, and simian crease.
Crigler-Najjar syndrome, Type I (glucuronyl transferase deficiency)
2
Autosomal-recessive; absence of hepatic uridine 5’-diphospho-glucuronosyltransferase activity
leading to unconjugated hyperbilirubinemia on 1st day of life without evidence of hemolysis;
requires phototherapy to prevent kernicterus.
Crigler-Najjar syndrome, Type II
Autosomal-recessive; less severe unconjugated hyperbilirubinemia due to partial activity of uridine
5’-diphospho-glucuronosyltransferase; kernicterus is less common than in Type I.
Cyclic neutropenia
Most often autosomal-dominant; lack of granulocyte macrophage colony-stimulating factor (GMCSF); characterized by fever, mouth lesions, cervical adenitis, and gastroenteritis occurring every 3–6
weeks; neutrophil count may be zero.
Diamond-Blackfan syndrome (congenital pure red cell aplasia)
Failure of erythropoiesis; characterized by macrocytic anemia, pallor, weakness, elevated fetal
hemoglobin, without hepatomegaly.
DiGeorge syndrome
Microdeletion of 22q11.2 most often; characterized by thymic hypoplasia or aplasia with
hypocalcemia; patients have tetany, seizures, abnormal facies, congenital heart disease, and
increased incidence of infection.
Dubin-Johnson syndrome
Autosomal-recessive; characterized by elevated conjugated bilirubin, large amounts of
coproporphyrin I in urine, and deposits of melanin like pigment in hepatocellular lysosomes.
Ehlers-Danlos syndrome
autosomal-dominant, variable expression (Type I); characterized by abnormal collagen leading to
hyperextensible joints and skin, poor wound healing with parchment-thin scars, narrow maxilla,
mitral valve prolapse, and aortic root dilatation. Types II-X has different modes of inheritance,
severity of disease, and related findings.
Eisenmenger syndrome
combination of pulmonary hypertension and right-to-left cardiac shunting within the heart that is
the progressive result of a structural heart defect that allows for left-to-right shunting and increased
pulmonary blood flow; over time, pulmonary hypertension develops with reversal of the shunt
direction; ventricular septal defects are the most common cause.
Fabry disease
X-linked deficiency of ceramide trihexosidase (alpha-galactosidase-A) leading to lipid storage
disease; characterized by tingling and burning in the hands and feet; small, red maculopapular
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lesions on the buttocks, inguinal area, fingernails, and lips; and an inability to perspire; proteinuria,
progressing to renal failure; increased risk of cardiovascular disease.
Fetal alcohol syndrome
Characterized by prenatal and postnatal growth deficiency, microcephaly, hypoplastic maxillary
bone; abnormal palpebral fissures; smooth philtrum with thin, smooth upper lip; epicanthal folds;
cardiac septal defect; delayed development; and mental deficiency.
Fetal hydantoin syndrome
Characterized by prenatal and postnatal growth deficiency, wide anterior fontanel, midface
hypoplasia, low nasal bridge, ocular hypertelorism, cupid bow upper lip, cleft lip and palate, mental
deficiency, and cardiac defects.
Fetal rubella syndrome
In utero rubella exposure (especially in the 1st trimester); characterized by mental deficiency,
microcephaly, deafness, cataract, glaucoma, patent ductus arteriosus, cardiac septal defects,
hepatosplenomegaly, anemia, and thrombocytopenia.
Fetal valproate syndrome
Midface hypoplasia, long philtrum, thin vermillion border, small mouth; aortic and ventricular
abnormalities; long, thin fingers and toes; meningomyelocele.
Fetal warfarin syndrome
Coumadin exposure, mostly in the 1st trimester, leading to nasal hypoplasia, mental deficiency, low
birth weight, mild hypoplasia of nails and fingers, and stippled epiphyses on radiographs.
Fragile X syndrome
X-linked in males and females, more easily recognized phenotype in males; characterized by mental
deficiency, autism or autistic like behaviours, macrocephaly, prognathism, dental crowding, large
ears, blue eyes, mild connective tissue dysplasia, and macro-orchidism.
Friedreich ataxia
autosomal-recessive; progressive loss of large myelinated axons in peripheral nerves, with
symptoms usually appearing in late childhood or adolescence; characterized by progressive
cerebellar and spinal cord dysfunction; patients have high-arched foot, hammer toes, and cardiac
failure.
Gardner syndrome
4
Autosomal-dominant; variant of familial adenomatous polyposis; characterized by multiple GI polyps
with malignant transformation, skin cysts, supernumerary teeth, and multiple osteoma.
Gaucher disease
Autosomal-recessive deficiency of glucocerebrosidase, leading to accumulation and storage of
glucocerebroside in the reticuloendothelial system; 3 types: (a) adult, or chronic, (b) acute
neuropathic, or infantile, (c) subacute neuropathic, or juvenile; characterized by splenomegaly,
hepatomegaly, delayed development, strabismus, swallowing difficulties, laryngeal spasm,
opisthotonos, and bone pain.
Gilbert syndrome
Generally autosomal-recessive; reduced activity of glucuronyl transferase activity leading to mild
unconjugated hyperbilirubinemia that worsens with stresses on the body, such as fasting.
Gilles de la Tourette syndrome
Dominant trait with partial penetrance; characterized by multiple motor and vocal tics that begin
before the age of 18; high rate of associated neurobehavioral difficulties, including obsessivecompulsive disorder, ADHD, anger control problems, and poor social skills.
Hartnup disease
Autosomal-recessive defect in transport of monoamine monocarboxylic amino acids by intestinal
mucosa and renal tubules; characterized by photosensitivity and a pellagra like skin rash; patients
may have cerebellar ataxia.
Histiocytosis X
Formerly called eosinophilic granuloma, Langerhans cell histiocytosis, Hand-Schuller-Christian
disease, or Letterer-Siwe disease; abnormal increase in macrophages, monocytes, and dendritic
cells; patients may have a few solitary bone lesions or seborrheic dermatitis of scalp,
lymphadenopathy, hepatosplenomegaly, tooth loss, exophthalmos, or pulmonary infiltrates; skull xrays notable for “punched out” lesions.
Holt-Oram syndrome
Autosomal-dominant with variable expression; characterized by upper limb defects (including
syndactyly, absent thumb, phocomelia), cardiac anomalies (including ostium secundum atrial septal
defect, ventricular septal defect), and narrow shoulders.
Hunter syndrome (mucopolysaccharidosis II)
X-linked recessive; involves an accumulation of heparan sulfate and dermatan sulfate and enzyme
deficiency of l-iduronate sulfatase; characterized by macrocephaly, coarse facial features,
hypertrophy of internal organs, and mental deficiency.
Hurler syndrome (mucopolysaccharidosis IH)
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autosomal-recessive; involves an accumulation of heparan sulfate and dermatan sulfate, and
enzyme deficiency of α-l-iduronidase; characterized by coarse facial features, growth arrest,
progressive mental deficiency, glaucoma, arthritis, and cardiac valvular disease.
Kallmann syndrome
Genetic hypogonadism; characterized by isolated gonadotropin deficiency and anosmia.
Kartagener syndrome
Autosomal-recessive; characterized by sinusitis, bronchiectasis, situs inversus, infertility and
immotile cilia.
Klinefelter syndrome
47 XXY karyotype; characterized by seminiferous tubule dysgenesis, testicular atrophy, eunuchoid
habitus, gynecomastia, and behaviour disorders.
Klippel-Feil syndrome
Due to a defect in cervical spine development; characterized by a short neck, limited neck motion,
and low occipital hairline. May also have associated genitourinary tract abnormalities.
LEOPARD syndrome
Autosomal-dominant with variable expression; characterized by lentigenes, EKG abnormalities,
ocular hypertelorism, pulmonic stenosis, abnormalities of genitalia, retardation of growth, and
deafness.
Lesch-Nyhan syndrome
X-linked disorder of purine metabolism; characterized by hyperuricemia as a result of diminished or
absent hypoxanthine guanine phosphoribosyl transferase (HPRT) activity, choreoathetosis,
compulsive self-mutilation, mental retardation, spastic cerebral palsy, and growth failure.
Marfan syndrome
Mutation of fibrillin gene on chromosome 15; connective tissue disorder characterized by ectopia
lentis, dilatation of the aorta, scoliosis, pneumothorax, pectus excavatum or carinatum, and long,
thin extremities.
McCune-Albright syndrome
Characterized by polyostotic fibrous dysplasia; multiple large café-au-lait macules with irregular
edges, and endocrinopathies such as precocious puberty, hyperthyroidism, gigantism and Cushing
syndrome; more commonly in girls.
MELAS syndrome
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(Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke like episodes); causes
seizures, hemiparesis, hemianopsia, or cortical blindness, sensorineural hearing loss, and short
stature.
Niemann-Pick disease
autosomal-recessive disorder of lipid metabolism with 4 subtypes; characterized by failure to thrive,
hepatomegaly, and rapidly progressive neurodegeneration; in its most severe form patients are
normal at birth but by 6 months experience delayed development and loss of developmental
milestones; 50% have a macular cherry red spot.
Noonan syndrome
autosomal-dominant; clinical features similar to Turner syndrome; characterized by cardiac disease
(most commonly or pulmonary valve stenosis), hypertelorism, downward palpebral slant, epicanthal
folds, webbed neck; short stature, and low set, posteriorly rotated ears; patients may also have
cryptorchidism, and a bleeding diathesis.
Osler-Weber-Rendu syndrome (hereditary hemorrhagic telangiectasia)
autosomal-dominant vascular dysplasia; characterized by telangiectases of the skin, respiratory tract
mucosa, lips, nails, and conjunctiva as well as arteriovenous malformations of the lung, liver, and
brain.
Osteogenesis imperfecta, Type I
Autosomal-dominant with variable expression; characterized by postnatal growth deficiency, fragile
bone with frequent fractures, hyperextensibility, blue sclerae, yellowish or bluish gray teeth, and
presenile deafness.
Osteogenesis imperfecta congenital (Type II)
mostly autosomal-dominant, but autosomal-recessive subtypes; characterized by short limbs, short
broad bones, and defective ossification, deep blue sclerae; usually stillborn or die in infancy of
respiratory failure.
Osteogenesis imperfecta, Type III
Autosomal-dominant; more severe than Type I, with prenatal growth deficiency, multiple fractures
present at birth, bluish sclera in infancy (normal in adulthood).
Osteogenesis imperfecta, Type IV
Autosomal-dominant; normal or moderate short stature, significant bone deformities, normal sclera,
femoral bowing in neonatal period that straightens with time.
Parinaud syndrome
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Characterized by weakness of upward gaze, nystagmus to convergence and accommodation,
pupillary changes, and eyelid retraction; classically seen with pineal tumours.
Peutz-Jeghers syndrome
Autosomal-dominant; characterized by melanotic macules on the lips and mucous membranes,
intestinal polyposis, and increased risk of malignancy.
Pickwickian syndrome
Characterized by obesity and hypoventilation; patients may have sleep apnea, daytime somnolence
and cyanosis.
Pierre Robin syndrome
Characterized by severe micrognathia, glossoptosis, and cleft palate.
Prader-Willi syndrome
autosomal-dominant disorder of chromosome 15 imprinting; characterized by hypotonia and initial
failure to thrive, followed by marked obesity due to an insatiable appetite; other features include
mental retardation, hypogonadism, small hands and feet, and short stature.
Rotor syndrome
Autosomal-recessive; characterized by mild conjugated bilirubinemia and jaundice that may be
exacerbated by infection, surgery, pregnancy, or drugs; usually asymptomatic with normal life
expectancy; clinically, similar to Dubin-Johnson; however, patients with Rotor have normal
appearing hepatocytes.
Sotos syndrome (cerebral gigantism)
Characterized by macrocephaly, large hands and feet, prominent mandible, rapid growth, mental
retardation, and poor coordination.
Sturge-Weber syndrome
characterized by a port-wine stain on the face at the 1st branch of the trigeminal nerve; patients
have ipsilateral leptomeningeal angiomatosis with intracranial calcifications leading to seizures and
mental retardation and may also have ocular complications, such as glaucoma.
Tay-Sachs disease (GM2-gangliosidosis type I)
autosomal-recessive, most common among Ashkenazi Jews (carrier state 1 in 25); characterized by
deficient hexosaminidase activity which leads to accumulation of GM2 gangliosides in the CNS;
patients have loss of motor milestones, seizures, macular cherry-red spot, and progressive
neurodegeneration leading to blindness, paralysis, and death within the 2nd or 3rd year of life.
Treacher Collins syndrome
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autosomal dominant with variable expression; characterized by mandibulofacial dysostosis; patients
have hypoplastic zygomatic arches and mandibles, micrognathia, downward slanting palpebral
fissures, coloboma of the lid, deformities of the external ear with associated conductive hearing
deficits, and a cleft palate with or without cleft lip.
Trisomy 13 (Patau syndrome)
Characterized by midline defects including holoprosencephaly, aplasia cutis congenital, cleft lip,
microphthalmia, postaxial polydactyly, clenched hands with overlapping fingers, and cardiovascular
anomalies; majority abort spontaneously and most live born infants die within the 1st year of life.
Trisomy 18 (Edwards syndrome)
Characterized by a small face, prominent occiput, micrognathia, low-set ears, clenched hands with
overriding fingers, a short sternum, and rocker bottom feet; patients are small for gestational age
and have severe mental retardation, cardiac and renal anomalies, and usually do not survive past the
1st year of life.
Trisomy 21 (Down syndrome)
Characterized by mental retardation and characteristic facies as well as congenital heart disease
(particularly atrioventricular canal defects), GI disorders (Hirschprung disease, duodenal atresia),
leukemia, hearing loss, and thyroid disease. One of the most common chromosomal abnormalities in
live born children.
Tuberous sclerosis
autosomal-dominant with highly variable expression; characterized by seizures, mental retardation,
intracranial tubers and subependymal calcification, retinal hamartomas, cardiac rhabdomyomas, and
renal hamartomas; pathognomonic skin lesions include hypopigmented macules (ash leaf spots),
connective tissue nevi (shagreen patch), adenoma sebaceum, and subungual or periungual fibromas.
Turcot syndrome
Characterized by adenomatous colonic polyposis associated with malignant brain tumours,
especially medulloblastoma and glioblastoma.
Turner syndrome
classically, 45 XO karyotype, another 15% are mosaic and may have less marked features;
characterized by gonadal dysplasia with sterility and primary amenorrhea, short stature, sparse
pubic and axillary hair and underdeveloped breasts with wide spaced nipples; also low hairline,
webbed neck, shield chest, congenital lymphedema of the extremities, cardiac disease (coarctation
of the aorta), and increased carrying angle.
VATER association
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Characterized by Vertebral defects, Anal atresia, Tracheoesophageal fistula with Esophageal atresia,
and Radial and/or renal anomalies; may be expanded to VACTERL to include Congenital heart
defects or other Limb defects.
Von Gierke disease (Glycogen Storage Disease Type I)
Autosomal-recessive inherited defect in glucose-6-phosphatase; characterized by fasting
hypoglycaemia, growth retardation, hepatomegaly, lactic acidosis, hyperlipidemia, and
hyperuricemia.
Von Hippel–Landau disease
autosomal dominant with variable penetrance (chromosome 3); neurocutaneous syndrome
predisposing to benign and malignant neoplasms, most commonly cerebellar, retinal or spinal
hemangioblastoma; associated with pheochromocytoma, renal cell carcinoma, pancreatic tumours
and cystic lesions of the kidneys, pancreas, liver, and epididymis.
Wegener granulomatosis
necrotizing granulomatous vasculitis involving (a) the airways, leading to rhinorrhea, chronic
sinusitis, nasal ulceration; (b) the lungs, causing hemoptysis, dyspnea and cough; (c) the kidneys,
manifested as hematuria and/or proteinuria due to glomerulonephritis; other symptoms include
fever, malaise, weight loss, myalgias, arthralgias, ophthalmic involvement, neuropathies, and
cutaneous nodules or ulcers.
Wiskott-Aldrich syndrome
X-linked recessive; characterized by thrombocytopenia, severe eczema, and recurrent infections.
Wolff-Parkinson-White syndrome
Accessory conduction pathway found in 25% of patients with supraventricular tachycardia; typical
electrocardiographic findings include a short PR interval and slow upstroke of the QRS (delta wave);
usually occurs in patients with a normal heart but also may occur in patients with Ebstein anomaly
and cardiomyopathy; slightly increased risk for sudden death due to cardiac arrhythmia.
Zollinger-Ellison syndrome
Characterized by gastrin secreting islet cell tumours leading to gastric acid hypersecretion and
production of duodenal and jejunal ulcers.
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A
Acanthosis nigricans
Achondroplasia
Adie syndrome
Alagille syndrome (arterio-hepatic dysplasia)
Alport syndrome
Asperger syndrome
Ataxia-telangiectasia syndrome (Louis-Bar syndrome)
1
1
1
1
1
1
1
B
Bartter syndrome
Behçet syndrome
Blind loop syndrome
Bronchiolitis obliterans
2
2
2
2
C
Cat-eye syndrome
Charcot-Marie-Tooth disease
Chédiak-Higashi syndrome
Cri du chat syndrome (5p deletion syndrome)
Crigler-Najjar syndrome, Type I (glucuronyl transferase deficiency)
Crigler-Najjar syndrome, Type II
Cyclic neutropenia
2
2
2
2
3
3
3
D
Diamond-Blackfan syndrome (congenital pure red cell aplasia)
DiGeorge syndrome
Dubin-Johnson syndrome
3
3
3
E
Ehlers-Danlos syndrome
Eisenmenger syndrome
3
3
F
Fabry disease
Fetal alcohol syndrome
Fetal hydantoin syndrome
Fetal rubella syndrome
Fetal valproate syndrome
Fetal warfarin syndrome
Fragile X syndrome
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4
4
4
4
4
4
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Friedreich ataxia
4
G
Gardner syndrome
Gaucher disease
Gilbert syndrome
Gilles de la Tourette syndrome
5
5
5
5
H
Hartnup disease
Histiocytosis X
Holt-Oram syndrome
Hunter syndrome (mucopolysaccharidosis II)
Hurler syndrome (mucopolysaccharidosis IH)
5
5
5
5
6
K
Kallmann syndrome
Kartagener syndrome
Klinefelter syndrome
Klippel-Feil syndrome
6
6
6
6
L
LEOPARD syndrome
Lesch-Nyhan syndrome
6
6
M
Marfan syndrome
McCune-Albright syndrome
MELAS syndrome
6
6
7
N
Niemann-Pick disease
Noonan syndrome
7
7
O
Osler-Weber-Rendu syndrome (hereditary hemorrhagic telangiectasia)
Osteogenesis imperfecta congenital (Type II)
Osteogenesis imperfecta, Type I
Osteogenesis imperfecta, Type III
Osteogenesis imperfecta, Type IV
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7
7
7
7
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P
Parinaud syndrome
Peutz-Jeghers syndrome
Pickwickian syndrome
Pierre Robin syndrome
Prader-Willi syndrome
8
8
8
8
8
R
Rotor syndrome
8
S
Sotos syndrome (cerebral gigantism)
Sturge-Weber syndrome
8
8
T
Tay-Sachs disease (GM2-gangliosidosis type I)
Treacher Collins syndrome
Trisomy 13 (Patau syndrome)
Trisomy 18 (Edwards syndrome)
Trisomy 21 (Down syndrome)
Tuberous sclerosis
Turcot syndrome
Turner syndrome
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9
9
9
9
9
9
9
V
VATER association
Von Gierke disease (Glycogen Storage Disease Type I)
Von Hippel–Landau disease
10
10
10
W
Wegener granulomatosis
Wiskott-Aldrich syndrome
Wolff-Parkinson-White syndrome
10
10
10
Z
Zollinger-Ellison syndrome
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13