U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Angelman syndrome(AS)

MedGen UID:
58144
Concept ID:
C0162635
Disease or Syndrome
Synonyms: AS; HAPPY PUPPET SYNDROME; Happy puppet syndrome (formerly)
SNOMED CT: Angelman's syndrome (76880004); Angelman syndrome (76880004); Happy puppet syndrome (76880004)
Modes of inheritance:
Unknown inheritance
MedGen UID:
989040
Concept ID:
CN307042
Finding
Source: Orphanet
Hereditary clinical entity whose mode of inheritance is unknown.
Not genetically inherited
MedGen UID:
988794
Concept ID:
CN307044
Finding
Source: Orphanet
clinical entity without genetic inheritance.
 
Genes (locations): SNRPN (15q11.2); UBE3A (15q11.2)
 
Monarch Initiative: MONDO:0007113
OMIM®: 105830
Orphanet: ORPHA72

Disease characteristics

Excerpted from the GeneReview: Angelman Syndrome
Angelman syndrome (AS) is characterized by severe developmental delay or intellectual disability, severe speech impairment, gait ataxia and/or tremulousness of the limbs, and unique behavior with an apparent happy demeanor that includes frequent laughing, smiling, and excitability. Microcephaly and seizures are also common. Developmental delays are first noted at around age six months; however, the unique clinical features of AS do not become manifest until after age one year. [from GeneReviews]
Authors:
Aditi I Dagli  |  Jennifer Mathews  |  Charles A Williams   view full author information

Additional descriptions

From OMIM
Angelman syndrome is a neurodevelopmental disorder characterized by mental retardation, movement or balance disorder, typical abnormal behaviors, and severe limitations in speech and language. Most cases are caused by absence of a maternal contribution to the imprinted region on chromosome 15q11-q13. Prader-Willi syndrome (PWS; 176270) is a clinically distinct disorder resulting from paternal deletion of the same 15q11-q13 region. In addition, the chromosome 15q11-q13 duplication syndrome (608636) shows overlapping clinical features. Clayton-Smith and Pembrey (1992) provided a review of Angelman syndrome. Cassidy and Schwartz (1998) reviewed the molecular and clinical aspects of both Prader-Willi syndrome and Angelman syndrome. Horsthemke and Wagstaff (2008) provided a detailed review of the mechanisms of imprinting of the Prader-Willi/Angelman syndrome region. Van Buggenhout and Fryns (2009) provided a review of Angelman syndrome and discussed genetic counseling of the disorder, which can show a recurrence risk of up to 50%, depending on the underlying genetic mechanism.  http://www.omim.org/entry/105830
From MedlinePlus Genetics
Angelman syndrome is a complex genetic disorder that primarily affects the nervous system. Characteristic features of this condition include delayed development, intellectual disability, severe speech impairment, and problems with movement and balance (ataxia). Most affected children also have recurrent seizures (epilepsy) and a small head size (microcephaly). Delayed development becomes noticeable by the age of 6 to 12 months, and other common signs and symptoms usually appear in early childhood.

Children with Angelman syndrome typically have a happy, excitable demeanor with frequent smiling, laughter, and hand-flapping movements. Hyperactivity and a short attention span are common. Most affected children also have difficulty sleeping and need less sleep than usual.

With age, people with Angelman syndrome become less excitable, and the sleeping problems tend to improve. However, affected individuals continue to have intellectual disability, severe speech impairment, and seizures throughout their lives. Adults with Angelman syndrome have distinctive facial features that may be described as "coarse." Other common features include unusually fair skin with light-colored hair and an abnormal side-to-side curvature of the spine (scoliosis). The life expectancy of people with this condition appears to be nearly normal.  https://medlineplus.gov/genetics/condition/angelman-syndrome

Clinical features

From HPO
Obesity
MedGen UID:
18127
Concept ID:
C0028754
Disease or Syndrome
Accumulation of substantial excess body fat.
Constipation
MedGen UID:
1101
Concept ID:
C0009806
Sign or Symptom
Infrequent or difficult evacuation of feces.
Feeding difficulties in infancy
MedGen UID:
436211
Concept ID:
C2674608
Finding
Impaired feeding performance of an infant as manifested by difficulties such as weak and ineffective sucking, brief bursts of sucking, and falling asleep during sucking. There may be difficulties with chewing or maintaining attention.
Cerebellar ataxia
MedGen UID:
849
Concept ID:
C0007758
Disease or Syndrome
Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly).
Seizure
MedGen UID:
20693
Concept ID:
C0036572
Sign or Symptom
A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.
Intellectual disability, severe
MedGen UID:
48638
Concept ID:
C0036857
Mental or Behavioral Dysfunction
Severe mental retardation is defined as an intelligence quotient (IQ) in the range of 20-34.
EEG abnormality
MedGen UID:
56235
Concept ID:
C0151611
Finding
Abnormality observed by electroencephalogram (EEG), which is used to record of the brain's spontaneous electrical activity from multiple electrodes placed on the scalp.
Hyperreflexia
MedGen UID:
57738
Concept ID:
C0151889
Finding
Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles.
Clumsiness
MedGen UID:
66690
Concept ID:
C0233844
Sign or Symptom
Lack of physical coordination resulting in an abnormal tendency to drop items or bump into objects.
Limb tremor
MedGen UID:
115980
Concept ID:
C0235081
Sign or Symptom
Delayed ability to walk
MedGen UID:
66034
Concept ID:
C0241726
Finding
A failure to achieve the ability to walk at an appropriate developmental stage. Most children learn to walk in a series of stages, and learn to walk short distances independently between 12 and 15 months.
Hyperactivity
MedGen UID:
98406
Concept ID:
C0424295
Finding
Hyperactivity is a condition characterized by constant and unusually high levels of activity, even in situations where it is deemed inappropriate.
Global developmental delay
MedGen UID:
107838
Concept ID:
C0557874
Finding
A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.
Broad-based gait
MedGen UID:
167799
Concept ID:
C0856863
Finding
An abnormal gait pattern in which persons stand and walk with their feet spaced widely apart. This is often a component of cerebellar ataxia.
Circadian rhythm sleep disorder
MedGen UID:
167920
Concept ID:
C0877792
Pathologic Function
Any abnormality of an individual's circadian rhythm that affects the timing of sleeping and being awake is referred to as a sleep-wake disorder.
Paroxysmal bursts of laughter
MedGen UID:
374299
Concept ID:
C1839749
Finding
Progressive gait ataxia
MedGen UID:
375309
Concept ID:
C1843885
Finding
A type of gait ataxia displaying progression of clinical severity.
Intellectual disability, progressive
MedGen UID:
337397
Concept ID:
C1846149
Mental or Behavioral Dysfunction
The term progressive intellectual disability should be used if intelligence decreases/deteriorates over time.
Motor delay
MedGen UID:
381392
Concept ID:
C1854301
Finding
A type of Developmental delay characterized by a delay in acquiring motor skills.
Absent speech
MedGen UID:
340737
Concept ID:
C1854882
Finding
Complete lack of development of speech and language abilities.
Happy demeanor
MedGen UID:
344654
Concept ID:
C1856115
Finding
A conspicuously happy disposition, characterized by frequent smiling and laughing, which may be contextually inappropriate or unrelated to the situation.
Cerebral cortical atrophy
MedGen UID:
1646740
Concept ID:
C4551583
Disease or Syndrome
Atrophy of the cortex of the cerebrum.
Hypotonia
MedGen UID:
10133
Concept ID:
C0026827
Finding
Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.
Scoliosis
MedGen UID:
11348
Concept ID:
C0036439
Disease or Syndrome
The presence of an abnormal lateral curvature of the spine.
Brachycephaly
MedGen UID:
113165
Concept ID:
C0221356
Congenital Abnormality
An abnormality of skull shape characterized by a decreased anterior-posterior diameter. That is, a cephalic index greater than 81%. Alternatively, an apparently shortened anteroposterior dimension (length) of the head compared to width.
Hypoplasia of the maxilla
MedGen UID:
66804
Concept ID:
C0240310
Congenital Abnormality
Abnormally small dimension of the Maxilla. Usually creating a malocclusion or malalignment between the upper and lower teeth or resulting in a deficient amount of projection of the base of the nose and lower midface region.
Secondary microcephaly
MedGen UID:
608952
Concept ID:
C0431352
Finding
Head circumference which falls below 2 standard deviations below the mean for age and gender because of insufficient head growth after birth.
Flat occiput
MedGen UID:
332439
Concept ID:
C1837402
Finding
Reduced convexity of the occiput (posterior part of skull).
Generalized hypotonia
MedGen UID:
346841
Concept ID:
C1858120
Finding
Generalized muscular hypotonia (abnormally low muscle tone).
Drooling
MedGen UID:
8484
Concept ID:
C0013132
Finding
Habitual flow of saliva out of the mouth.
Macroglossia
MedGen UID:
44236
Concept ID:
C0024421
Disease or Syndrome
Increased length and width of the tongue.
Wide mouth
MedGen UID:
44238
Concept ID:
C0024433
Congenital Abnormality
Distance between the oral commissures more than 2 SD above the mean. Alternatively, an apparently increased width of the oral aperture (subjective).
Protruding tongue
MedGen UID:
66831
Concept ID:
C0241442
Finding
Tongue extending beyond the alveolar ridges or teeth at rest.
Mandibular prognathia
MedGen UID:
98316
Concept ID:
C0399526
Finding
Abnormal prominence of the chin related to increased length of the mandible.
Widely spaced teeth
MedGen UID:
337093
Concept ID:
C1844813
Finding
Increased spaces (diastemata) between most of the teeth in the same dental arch.
Hypopigmentation of the skin
MedGen UID:
102477
Concept ID:
C0162835
Disease or Syndrome
A reduction of skin color related to a decrease in melanin production and deposition.
Fair hair
MedGen UID:
336542
Concept ID:
C1849221
Finding
A lesser degree of hair pigmentation than would otherwise be expected.
Exotropia
MedGen UID:
4613
Concept ID:
C0015310
Disease or Syndrome
A form of strabismus with one or both eyes deviated outward.
Myopia
MedGen UID:
44558
Concept ID:
C0027092
Disease or Syndrome
Nearsightedness, also known as myopia, is an eye condition that causes blurry distance vision. People who are nearsighted have more trouble seeing things that are far away (such as when driving) than things that are close up (such as when reading or using a computer). If it is not treated with corrective lenses or surgery, nearsightedness can lead to squinting, eyestrain, headaches, and significant visual impairment.\n\nNearsightedness usually begins in childhood or adolescence. It tends to worsen with age until adulthood, when it may stop getting worse (stabilize). In some people, nearsightedness improves in later adulthood.\n\nFor normal vision, light passes through the clear cornea at the front of the eye and is focused by the lens onto the surface of the retina, which is the lining of the back of the eye that contains light-sensing cells. People who are nearsighted typically have eyeballs that are too long from front to back. As a result, light entering the eye is focused too far forward, in front of the retina instead of on its surface. It is this change that causes distant objects to appear blurry. The longer the eyeball is, the farther forward light rays will be focused and the more severely nearsighted a person will be.\n\nNearsightedness is measured by how powerful a lens must be to correct it. The standard unit of lens power is called a diopter. Negative (minus) powered lenses are used to correct nearsightedness. The more severe a person's nearsightedness, the larger the number of diopters required for correction. In an individual with nearsightedness, one eye may be more nearsighted than the other.\n\nEye doctors often refer to nearsightedness less than -5 or -6 diopters as "common myopia." Nearsightedness of -6 diopters or more is commonly called "high myopia." This distinction is important because high myopia increases a person's risk of developing other eye problems that can lead to permanent vision loss or blindness. These problems include tearing and detachment of the retina, clouding of the lens (cataract), and an eye disease called glaucoma that is usually related to increased pressure within the eye. The risk of these other eye problems increases with the severity of the nearsightedness. The term "pathological myopia" is used to describe cases in which high myopia leads to tissue damage within the eye.
Nystagmus
MedGen UID:
45166
Concept ID:
C0028738
Disease or Syndrome
Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.
Strabismus
MedGen UID:
21337
Concept ID:
C0038379
Disease or Syndrome
A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error.
Deeply set eye
MedGen UID:
473112
Concept ID:
C0423224
Finding
An eye that is more deeply recessed into the plane of the face than is typical.
Blue irides
MedGen UID:
108297
Concept ID:
C0578626
Finding
A markedly blue coloration of the iris.

Professional guidelines

PubMed

Keary CJ, McDougle CJ
Expert Rev Neurother 2023 Jul-Dec;23(9):835-844. Epub 2023 Aug 21 doi: 10.1080/14737175.2023.2245568. PMID: 37599585
Duis J, Nespeca M, Summers J, Bird L, Bindels-de Heus KGCB, Valstar MJ, de Wit MY, Navis C, Ten Hooven-Radstaake M, van Iperen-Kolk BM, Ernst S, Dendrinos M, Katz T, Diaz-Medina G, Katyayan A, Nangia S, Thibert R, Glaze D, Keary C, Pelc K, Simon N, Sadhwani A, Heussler H, Wheeler A, Woeber C, DeRamus M, Thomas A, Kertcher E, DeValk L, Kalemeris K, Arps K, Baym C, Harris N, Gorham JP, Bohnsack BL, Chambers RC, Harris S, Chambers HG, Okoniewski K, Jalazo ER, Berent A, Bacino CA, Williams C, Anderson A
Mol Genet Genomic Med 2022 Mar;10(3):e1843. Epub 2022 Feb 11 doi: 10.1002/mgg3.1843. PMID: 35150089Free PMC Article
Yang L, Shu X, Mao S, Wang Y, Du X, Zou C
Genes (Basel) 2021 Jun 28;12(7) doi: 10.3390/genes12070987. PMID: 34203304Free PMC Article

Curated

Eurogentest, 2008

Recent clinical studies

Etiology

Holm A, Hansen SN, Klitgaard H, Kauppinen S
RNA Biol 2022;19(1):594-608. Epub 2021 Dec 31 doi: 10.1080/15476286.2022.2066334. PMID: 35482908Free PMC Article
Duis J, Nespeca M, Summers J, Bird L, Bindels-de Heus KGCB, Valstar MJ, de Wit MY, Navis C, Ten Hooven-Radstaake M, van Iperen-Kolk BM, Ernst S, Dendrinos M, Katz T, Diaz-Medina G, Katyayan A, Nangia S, Thibert R, Glaze D, Keary C, Pelc K, Simon N, Sadhwani A, Heussler H, Wheeler A, Woeber C, DeRamus M, Thomas A, Kertcher E, DeValk L, Kalemeris K, Arps K, Baym C, Harris N, Gorham JP, Bohnsack BL, Chambers RC, Harris S, Chambers HG, Okoniewski K, Jalazo ER, Berent A, Bacino CA, Williams C, Anderson A
Mol Genet Genomic Med 2022 Mar;10(3):e1843. Epub 2022 Feb 11 doi: 10.1002/mgg3.1843. PMID: 35150089Free PMC Article
Buiting K, Williams C, Horsthemke B
Nat Rev Neurol 2016 Oct;12(10):584-93. Epub 2016 Sep 12 doi: 10.1038/nrneurol.2016.133. PMID: 27615419
Blackmer AB, Feinstein JA
Pharmacotherapy 2016 Jan;36(1):84-98. doi: 10.1002/phar.1686. PMID: 26799351
Eggermann T
Am J Med Genet C Semin Med Genet 2010 Aug 15;154C(3):355-64. doi: 10.1002/ajmg.c.30274. PMID: 20803658

Diagnosis

Duis J, Nespeca M, Summers J, Bird L, Bindels-de Heus KGCB, Valstar MJ, de Wit MY, Navis C, Ten Hooven-Radstaake M, van Iperen-Kolk BM, Ernst S, Dendrinos M, Katz T, Diaz-Medina G, Katyayan A, Nangia S, Thibert R, Glaze D, Keary C, Pelc K, Simon N, Sadhwani A, Heussler H, Wheeler A, Woeber C, DeRamus M, Thomas A, Kertcher E, DeValk L, Kalemeris K, Arps K, Baym C, Harris N, Gorham JP, Bohnsack BL, Chambers RC, Harris S, Chambers HG, Okoniewski K, Jalazo ER, Berent A, Bacino CA, Williams C, Anderson A
Mol Genet Genomic Med 2022 Mar;10(3):e1843. Epub 2022 Feb 11 doi: 10.1002/mgg3.1843. PMID: 35150089Free PMC Article
Yang L, Shu X, Mao S, Wang Y, Du X, Zou C
Genes (Basel) 2021 Jun 28;12(7) doi: 10.3390/genes12070987. PMID: 34203304Free PMC Article
Blackmer AB, Feinstein JA
Pharmacotherapy 2016 Jan;36(1):84-98. doi: 10.1002/phar.1686. PMID: 26799351
Margolis SS, Sell GL, Zbinden MA, Bird LM
Neurotherapeutics 2015 Jul;12(3):641-50. doi: 10.1007/s13311-015-0361-y. PMID: 26040994Free PMC Article
Kalsner L, Chamberlain SJ
Pediatr Clin North Am 2015 Jun;62(3):587-606. Epub 2015 Apr 22 doi: 10.1016/j.pcl.2015.03.004. PMID: 26022164Free PMC Article

Therapy

Holm A, Hansen SN, Klitgaard H, Kauppinen S
RNA Biol 2022;19(1):594-608. Epub 2021 Dec 31 doi: 10.1080/15476286.2022.2066334. PMID: 35482908Free PMC Article
Samanta D
Brain Dev 2021 Jan;43(1):32-44. Epub 2020 Sep 4 doi: 10.1016/j.braindev.2020.08.014. PMID: 32893075Free PMC Article
Jakaria M, Azam S, Haque ME, Jo SH, Uddin MS, Kim IS, Choi DK
Redox Biol 2019 Jun;24:101223. Epub 2019 May 21 doi: 10.1016/j.redox.2019.101223. PMID: 31141786Free PMC Article
Blackmer AB, Feinstein JA
Pharmacotherapy 2016 Jan;36(1):84-98. doi: 10.1002/phar.1686. PMID: 26799351
Margolis SS, Sell GL, Zbinden MA, Bird LM
Neurotherapeutics 2015 Jul;12(3):641-50. doi: 10.1007/s13311-015-0361-y. PMID: 26040994Free PMC Article

Prognosis

Heussler HS
Curr Opin Psychiatry 2021 Mar 1;34(2):123-128. doi: 10.1097/YCO.0000000000000674. PMID: 33395098
Zylka MJ
Autism Res 2020 Jan;13(1):11-17. Epub 2019 Sep 6 doi: 10.1002/aur.2203. PMID: 31490639Free PMC Article
Bonello D, Camilleri F, Calleja-Agius J
Neonatal Netw 2017 May 1;36(3):142-151. doi: 10.1891/0730-0832.36.3.142. PMID: 28494826
Adams DJ, Clark DA
Pediatr Clin North Am 2015 Apr;62(2):411-26. Epub 2015 Jan 22 doi: 10.1016/j.pcl.2014.11.005. PMID: 25836705
Zori RT, Hendrickson J, Woolven S, Whidden EM, Gray B, Williams CA
J Child Neurol 1992 Jul;7(3):270-80. doi: 10.1177/088307389200700307. PMID: 1634750

Clinical prediction guides

Paprocka J, Coppola A, Cuccurullo C, Stawicka E, Striano P
Epilepsia Open 2024 Aug;9(4):1192-1232. Epub 2024 Jun 4 doi: 10.1002/epi4.12951. PMID: 38837855Free PMC Article
Donnan AM, Schneider AL, Russ-Hall S, Churilov L, Scheffer IE
Neurology 2023 Apr 18;100(16):e1712-e1722. Epub 2023 Feb 7 doi: 10.1212/WNL.0000000000207080. PMID: 36750385Free PMC Article
Frohlich J, Toker D, Monti MM
Brain 2021 Sep 4;144(8):2257-2277. doi: 10.1093/brain/awab095. PMID: 33693596
Zylka MJ
Autism Res 2020 Jan;13(1):11-17. Epub 2019 Sep 6 doi: 10.1002/aur.2203. PMID: 31490639Free PMC Article
Eggermann T
Am J Med Genet C Semin Med Genet 2010 Aug 15;154C(3):355-64. doi: 10.1002/ajmg.c.30274. PMID: 20803658

Recent systematic reviews

Bergonzini L, Pruccoli J, Pettenuzzo I, Pugliano R, Soliani L, Fetta A, Cordelli DM
Genes (Basel) 2023 Jan 23;14(2) doi: 10.3390/genes14020299. PMID: 36833226Free PMC Article
Shaffer RC, Reisinger DL, Schmitt LM, Lamy M, Dominick KC, Smith EG, Coffman MC, Esbensen AJ
J Am Acad Child Adolesc Psychiatry 2023 May;62(5):518-557. Epub 2022 Aug 22 doi: 10.1016/j.jaac.2022.06.020. PMID: 36007813
Hajtovic S, LoPresti MA, Zhang L, Katlowitz KA, Kizek DJ, Lam S
J Neurosurg Pediatr 2022 Jun 1;29(6):667-680. Epub 2022 Mar 18 doi: 10.3171/2022.1.PEDS222. PMID: 35303699
Bell L, Wittkowski A, Hare DJ
J Autism Dev Disord 2019 Jan;49(1):54-67. doi: 10.1007/s10803-018-3658-y. PMID: 30014250Free PMC Article
Veltman MW, Craig EE, Bolton PF
Psychiatr Genet 2005 Dec;15(4):243-54. doi: 10.1097/00041444-200512000-00006. PMID: 16314754

Supplemental Content

Table of contents

    Clinical resources

    Practice guidelines

    • PubMed
      See practice and clinical guidelines in PubMed. The search results may include broader topics and may not capture all published guidelines. See the FAQ for details.
    • Bookshelf
      See practice and clinical guidelines in NCBI Bookshelf. The search results may include broader topics and may not capture all published guidelines. See the FAQ for details.

    Curated

    Recent activity

    Your browsing activity is empty.

    Activity recording is turned off.

    Turn recording back on

    See more...