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Congenital cerebellar hypoplasia(CHEGDD)

MedGen UID:
Concept ID:
Disease or Syndrome
Synonyms: Cerebellar hypoplasia/atrophy, epilepsy, and global developmental delay; CHEGDD; Isolated cerebellar hypoplasia/agenesis
Gene (location): OXR1 (8q23.1)
Monarch Initiative: MONDO:0008939
OMIM®: 213000
Orphanet: ORPHA1398


Cerebellar hypoplasia/atrophy, epilepsy, and global developmental delay is an autosomal recessive neurodevelopmental disorder characterized by infantile onset of hypotonia and developmental delay with subsequent impaired intellectual development and severe speech delay. In childhood, affected individuals show delayed walking and develop epilepsy that is usually controlled by medication. Brain imaging shows cerebellar hypoplasia/atrophy (summary by Wang et al., 2019). [from OMIM]

Clinical features

From HPO
Cerebellar ataxia
MedGen UID:
Concept ID:
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).
MedGen UID:
Concept ID:
Sign or Symptom
An unintentional, oscillating to-and-fro muscle movement about a joint axis.
Cerebellar hypoplasia
MedGen UID:
Concept ID:
Congenital Abnormality
Cerebellar hypoplasia is a descriptive term implying a cerebellum with a reduced volume, but a normal shape and is stable over time.
MedGen UID:
Concept ID:
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.
Generalized hypotonia
MedGen UID:
Concept ID:
Generalized muscular hypotonia (abnormally low muscle tone).
MedGen UID:
Concept ID:
Disease or Syndrome
Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVCongenital cerebellar hypoplasia

Professional guidelines


Mandel AM
Handb Clin Neurol 2020;171:291-311. doi: 10.1016/B978-0-444-64239-4.00015-1. PMID: 32736756
Kau T, Marterer R, Kottke R, Birnbacher R, Gellen J, Nagy E, Boltshauser E
Clin Neuroradiol 2020 Sep;30(3):435-445. Epub 2020 Jan 15 doi: 10.1007/s00062-019-00871-4. PMID: 31942658
Malinger G, Lev D, Lerman-Sagie T
Prenat Diagn 2009 Apr;29(4):372-80. doi: 10.1002/pd.2196. PMID: 19194867

Recent clinical studies


al Shahwan SA, Bruyn GW, al Deeb SM
J Neurol Sci 1995 Jan;128(1):71-7. doi: 10.1016/0022-510x(94)00209-7. PMID: 7722536


Abs R, Van Vleymen E, Parizel PM, Van Acker K, Martin M, Martin JJ
J Neurol Sci 1990 Sep;98(2-3):259-65. doi: 10.1016/0022-510x(90)90267-q. PMID: 2243234

Clinical prediction guides

Illarioshkin SN, Tanaka H, Markova ED, Nikolskaya NN, Ivanova-Smolenskaya IA, Tsuji S
Ann Neurol 1996 Jul;40(1):75-83. doi: 10.1002/ana.410400113. PMID: 8687195

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