Information
Last updated: 28 June 2024

Opitz-Kaveggia Syndrome (OKS)

Information
FG SyndromeOpitz-Kaveggia Syndrome (OKS)
  • Description

    • An X-linked recessive mental retardation syndrome.
    • Characterized by:
      • Dysmorphic features: relative macrocephaly, hypertelorism, downslanted palpebral fissures, prominent forehead with frontal hair upsweep, broad thumbs, and halluces.
      • Hypotonia, constipation, partial agenesis of the corpus callosum.
      • Some patients exhibit sensorineural hearing loss, joint laxity evolving into joint contractures.
      • Hyperactivity and talkativeness are common.
  • History

    • Initially described as 'FG syndrome' by Opitz and Kaveggia in 1974, using the initials of patients' surnames.
  • Genetic Heterogeneity

    • Different forms of 'FG syndrome' identified:
      • FGS2: Mutation in the FLNA gene (Xq28).
      • FGS4: Mutation in the CASK gene (Xp11).
      • FGS3: Mapped to Xp22.3.
      • FGS5: Mapped to Xq22.3.
    • MED12 gene mutation should be reserved for Opitz-Kaveggia syndrome.
  • Clinical Features

    • Initial descriptions included mental retardation, large head, imperforate anus, congenital hypotonia, and partial agenesis of the corpus callosum.
    • Additional features include short stature, joint contractures, seizures, gastrointestinal defects, and congenital heart defects.
    • Features such as broad great toes and frontal upsweep of hair have been observed in unrelated families.
    • Associated features: sensorineural deafness, severe constipation, telecanthus, hypertelorism, macrocephaly, characteristic facial appearance, and personality traits.
    • Behavioral characteristics include socially oriented and attention-seeking behaviors similar to Williams syndrome.
  • Diagnosis

    • Defined as an X-linked multiple congenital anomaly-cognitive impairment disorder caused by the R961W mutation in the MED12 gene.
    • Clinical criteria include small ears, characteristic facial features, congenital anomalies, and a distinctive personality.
  • Mapping

    • Linkage analysis identified linkage to DXS441 at Xq13, confirming genetic heterogeneity.
    • Inversion inv(X)(q12q28) associated with FG syndrome in some families.
  • Molecular Genetics

    • MED12 gene, located at Xq13, influences thyroid function and is implicated in X-linked mental retardation.

Reference

Online Mendelian Inheritance in Man (OMIM). (2024). OPITZ-KAVEGGIA SYNDROME. Retrieved June 28, 2024, from https://www.omim.org/entry/305450


Cite this: ICNApedia contributors.Opitz-Kaveggia Syndrome (OKS). ICNApedia, The Child Neurology Knowledge Environment. 09 November 2024. Available at: https://icnapedia.org/knowledgebase/articles/opitz-kaveggia-syndrome-oks Accessed  09 November 2024. 

Related Articles


Text is available under the Cc by nc sa iconCC Attribution-Noncommercial-Share Alike 4.0 International; additional terms may apply.