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Spongy degeneration of central nervous system

MedGen UID:
61565
Concept ID:
C0206307
Disease or Syndrome
Synonyms: ACY2 deficiency; Aminoacylase 2 deficiency; ASP deficiency; Aspartoacylase deficiency; Canavan disease; Canavan-van Bogaert-Bertrand disease; Spongy degeneration of the central nervous system; Von Bogaert-Bertrand disease
SNOMED CT: Spongy degeneration of central nervous system (80544005); Spongy degeneration of white matter (80544005); Canavan's disease (80544005); Canavan-van Bogaert-Bertrand disease (80544005); Canavan-van-Bogaert-Bertrand disease (80544005); Aspartoacylase deficiency (80544005); Spongy degeneration of white matter in infancy (80544005); Spongiform leucodystrophy (80544005)
Modes of inheritance:
Autosomal recessive inheritance
MedGen UID:
141025
Concept ID:
C0441748
Intellectual Product
Source: Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele).
 
Gene (location): ASPA (17p13.2)
 
Monarch Initiative: MONDO:0010079
OMIM®: 271900
Orphanet: ORPHA141

Disease characteristics

Excerpted from the GeneReview: Canavan Disease
Canavan disease is a leukodystrophy characterized by neurodevelopmental delays, macrocephaly, and tone abnormalities. The phenotypic spectrum ranges from the more severe typical Canavan disease (85%-90% of individuals) to the less severe atypical Canavan disease (10%-15%). Typical Canavan disease is characterized by neurodevelopmental impairment evident by ages three to five months, followed by neurodegeneration and developmental regression. The clinical course of atypical Canavan disease is more variable, with neurodevelopmental delay usually becoming evident in the first years of life and frequently followed by developmental regression later in childhood or adolescence. All individuals with Canavan disease have reduced life expectancy, with the majority surviving to age ten years and the minority living to adulthood. [from GeneReviews]
Authors:
Amanda Nagy  |  Annette E Bley  |  Florian Eichler   view full author information

Additional description

From MedlinePlus Genetics
Canavan disease is a rare inherited disorder that damages the ability of nerve cells (neurons) in the brain to send and receive messages. This disease is one of a group of genetic disorders called leukodystrophies. Leukodystrophies disrupt the growth or maintenance of the myelin sheath, which is the covering that protects nerves and promotes the efficient transmission of nerve impulses.

The life expectancy for people with Canavan disease varies. Most people with the neonatal/infantile form live only into childhood, although some survive into adolescence or beyond. People with the mild/juvenile form do not appear to have a shortened lifespan.

Neonatal/infantile Canavan disease is the most common and most severe form of the condition. Affected infants appear normal for the first few months of life, but by age 3 to 5 months, problems with development become noticeable. These infants usually do not develop motor skills such as turning over, controlling head movement, and sitting without support. Other common features of this condition include weak muscle tone (hypotonia), an unusually large head size (macrocephaly), and irritability. Feeding and swallowing difficulties, seizures, and sleep disturbances may also develop.

The mild/juvenile form of Canavan disease is less common. Affected individuals have mildly delayed development of speech and motor skills starting in childhood. These delays may be so mild and nonspecific that they are never recognized as being caused by Canavan disease.  https://medlineplus.gov/genetics/condition/canavan-disease

Clinical features

From HPO
Elevated urine N-acetylaspartic acid level
MedGen UID:
1841756
Concept ID:
C5826558
Finding
The amount of N-acetylaspartate in the urine, when corrected for urine concentration, is above upper limit of normal. This feature can be measured using gas chromatography-mass spectrometry.
Hearing impairment
MedGen UID:
235586
Concept ID:
C1384666
Disease or Syndrome
A decreased magnitude of the sensory perception of sound.
Opisthotonus
MedGen UID:
56246
Concept ID:
C0151818
Sign or Symptom
Abnormal pyramidal sign
MedGen UID:
68582
Concept ID:
C0234132
Sign or Symptom
Functional neurological abnormalities related to dysfunction of the pyramidal tract.
CNS demyelination
MedGen UID:
137898
Concept ID:
C0338474
Disease or Syndrome
A loss of myelin from nerve fibers in the central nervous system.
Bilateral tonic-clonic seizure
MedGen UID:
141670
Concept ID:
C0494475
Sign or Symptom
A bilateral tonic-clonic seizure is a seizure defined by a tonic (bilateral increased tone, lasting seconds to minutes) and then a clonic (bilateral sustained rhythmic jerking) phase.
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.
Hypsarrhythmia
MedGen UID:
195766
Concept ID:
C0684276
Finding
Hypsarrhythmia is abnormal interictal high amplitude waves and a background of irregular spikes. There is continuous (during wakefulness), high-amplitude (>200 Hz), generalized polymorphic slowing with no organized background and multifocal spikes demonstrated by electroencephalography (EEG).
Epileptic spasm
MedGen UID:
315948
Concept ID:
C1527366
Disease or Syndrome
A sudden flexion, extension, or mixed extension-flexion of predominantly proximal and truncal muscles that is usually more sustained than a myoclonic movement but not as sustained as a tonic seizure. Limited forms may occur
Developmental regression
MedGen UID:
324613
Concept ID:
C1836830
Disease or Syndrome
Loss of developmental skills, as manifested by loss of developmental milestones.
Multifocal epileptiform discharges
MedGen UID:
866864
Concept ID:
C4021219
Finding
An abnormality in cerebral electrical activity recorded along the scalp by electroencephalography (EEG) and being identified at multiple locations (foci).
Elevated brain N-acetyl aspartate level by MRS
MedGen UID:
1369723
Concept ID:
C4476572
Finding
An increase in the level of N-acetyl aspartate in the brain identified by magnetic resonance spectroscopy (MRS).
Brain atrophy
MedGen UID:
1643639
Concept ID:
C4551584
Disease or Syndrome
Partial or complete wasting (loss) of brain tissue that was once present.
Increased CSF N-acetylaspartic acid concentration
MedGen UID:
1689724
Concept ID:
C5139236
Finding
An abnormally increased concentration of N-acetylaspartic acid in the cerebrospinal fluid (CSF).
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.
Macrocephaly
MedGen UID:
745757
Concept ID:
C2243051
Finding
Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium.
Delayed closure of the anterior fontanelle
MedGen UID:
825928
Concept ID:
C3840083
Finding
A delay in closure (ossification) of the anterior fontanelle, which generally undergoes closure around the 18th month of life.
Microcephaly
MedGen UID:
1644158
Concept ID:
C4551563
Finding
Head circumference below 2 standard deviations below the mean for age and gender.
Increased circulating N-acetylaspartic acid concentration
MedGen UID:
1701810
Concept ID:
C5139235
Finding
Concentration of N-acetylaspartic acid in the blood circulation above the upper limit of normal.
Reduced aspartoacylase activity in cultured fibroblasts
MedGen UID:
1054465
Concept ID:
CN377162
Finding
Activity of aspartoacylase below the lower limit of normal in cultured fibroblasts. Aspartoacylase (EC 3.5.1.15), also called aminoacylase-2, is an enzyme that hydrolyzes N-acetyl-L-aspartic acid (NAA) to aspartate and acetate.
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.
Optic atrophy
MedGen UID:
18180
Concept ID:
C0029124
Disease or Syndrome
Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy.
Blindness
MedGen UID:
99138
Concept ID:
C0456909
Disease or Syndrome
Blindness is the condition of lacking visual perception defined as a profound reduction in visual perception. On the 6m visual acuity scale, blindness is defined as less than 3/60. On the 20ft visual acuity scale, blindness is defined as less than 20/400. On the decimal visual acuity scale, blindness is defined as less than 0.05. Blindness is typically characterized by a visual field of no greater than 10 degrees in radius around central fixation.
Visual impairment
MedGen UID:
777085
Concept ID:
C3665347
Finding
Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery.

Professional guidelines

PubMed

McEvoy JW, McCarthy CP, Bruno RM, Brouwers S, Canavan MD, Ceconi C, Christodorescu RM, Daskalopoulou SS, Ferro CJ, Gerdts E, Hanssen H, Harris J, Lauder L, McManus RJ, Molloy GJ, Rahimi K, Regitz-Zagrosek V, Rossi GP, Sandset EC, Scheenaerts B, Staessen JA, Uchmanowicz I, Volterrani M, Touyz RM; ESC Scientific Document Group
Eur Heart J 2024 Oct 7;45(38):3912-4018. doi: 10.1093/eurheartj/ehae178. PMID: 39210715
Bradbury AM, Ream MA
Semin Pediatr Neurol 2021 Apr;37:100876. Epub 2021 Feb 10 doi: 10.1016/j.spen.2021.100876. PMID: 33892849
Pleasure D, Guo F, Chechneva O, Bannerman P, McDonough J, Burns T, Wang Y, Hull V
Neurochem Res 2020 Mar;45(3):561-565. Epub 2018 Dec 8 doi: 10.1007/s11064-018-2693-6. PMID: 30535831Free PMC Article

Curated

American College of Medical Genetics ACT Sheet, Carrier Screening ACT Sheet Ashkenazi Jewish Genetic Disorders

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    • 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.
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      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

    • ACMG ACT, 2011
      American College of Medical Genetics ACT Sheet, Carrier Screening ACT Sheet Ashkenazi Jewish Genetic Disorders

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