Infantile cerebellar retinal degeneration explained

Infantile cerebellar retinal degeneration
Synonyms:Infantile cerebellar-retinal degeneration, ICRD
Symptoms:brain and ocular complications
Complications:vision loss, intellectual disabilities
Onset:age of 6 months old
Duration:Life-long
Frequency:Rare, only 26 cases have been recorded in medical literature

Infantile cerebellar retinal degeneration is a rare hereditary neurological disorder which primarily affects the eyes and the brain.[1]

Presentation

Babies with this condition usually appear normal at birth, but start showing symptoms when they are just 6 months old, these symptoms are (but are not limited to): hypotonia, developmental delays, seizures, bobbing of the head, abnormal twitching and movement of the muscles, and loss of braincells from the cerebellum, retinal degeneration, involuntary rapid movement of the eyes, and strabismus.[2] [3] [4] [5]

Causes

This condition is caused by mutations in the ACO2 gene,[6] [7] located on chromosome 22q13.2, these mutations are inherited in an autosomal recessive fashion, meaning that if both parents carry one copy of the disease-causing mutation, there is a 25% (1 in 4) chance their children will develop the disease.[8]

Normally, this gene produces a protein/enzyme that catalyzes the interconversion of citrate to isocitrate via cis-aconitate in the second step of the TCA cycle.

Etiology

The first case report of this disorder was in 2012, when affected 8 members from 2 Arab-Muslim families, most of the patients were brought to the doctor when they were between 2 and 6 months of age, with most of the symptoms described before.

Since then, 6 more case reports (including more than one person) reporting new cases and/or studying the disease have been documented, leaving us with a total of 26 people with the disease recorded in global medical literature.[9]

Notes and References

  1. Web site: Orphanet: Infantile cerebellar retinal degeneration .
  2. Web site: Infantile Cerebellar-Retinal Degeneration Hereditary Ocular Diseases . 2022-05-04 . disorders.eyes.arizona.edu.
  3. Web site: Infantile cerebellar retinal degeneration - About the Disease - Genetic and Rare Diseases Information Center . 2022-05-04 . rarediseases.info.nih.gov . en.
  4. Web site: Infantile cerebellar retinal degeneration . 2022-05-04 . NORD (National Organization for Rare Disorders) . en-US.
  5. Web site: 2021-01-15 . Rare Disease Series #17: Infantile Cerebellar-retinal Degeneration . 2022-05-04 . 3billion Blog.
  6. Ha . Dong Jun . Park . Jisun . Seo . Go Hun . Lee . Kyoungyeul . Kwon . Young Se . Lee . Ji Eun . Kim . Su Jin . 2022 . Case Report: Infantile Cerebellar-Retinal Degeneration With Compound Heterozygous Variants in ACO2 Gene—Long-Term Follow-Up of a Sibling . Frontiers in Genetics . 13 . 729980 . 10.3389/fgene.2022.729980 . 35368710 . 8965713 . 1664-8021. free .
  7. Infantile Cerebellar-Retinal Degeneration Associated with a Mutation in Mitochondrial Aconitase, ACO2. 2012 . 3309186 . Spiegel . R. . Pines . O. . Ta-Shma . A. . Burak . E. . Shaag . A. . Halvardson . J. . Edvardson . S. . Mahajna . M. . Zenvirt . S. . Saada . A. . Shalev . S. . Feuk . L. . Elpeleg . O. . American Journal of Human Genetics . 90 . 3 . 518–523 . 10.1016/j.ajhg.2012.01.009 . 22405087 .
  8. Web site: Infantile Cerebellar-Retinal Degeneration (ICRD). 2022-05-04 . www.malacards.org.
  9. Web site: OMIM Entry - # 614559 - INFANTILE CEREBELLAR-RETINAL DEGENERATION; ICRD . 2022-05-04 . omim.org . en-us.