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Ring chromosome 12 syndrome

Disease definition

Ring chromosome 12 syndrome is a rare chromosomal anomaly syndrome with a highly variable phenotype principally characterized by postnatal growth retardation, variable degrees of developmental delay and intellectual disability, microcephaly and facial dysmorphism (incl. epicanthal folds, low-set, cupped ears, prominent nose with flat nasal bridge, high arched palate, micrognathia). Skeletal abnormalities (e.g. pectus excavatum, clinodactyly), congenital heart malformations, cryptorchidism, café-au-lait spots and epilepsy have also been reported.


  • Synonym(s):
    • Ring 12
    • Ring chromosome 12
  • Prevalence: <1 / 1 000 000
  • Inheritance: -
  • Age of onset: -
  • ICD-10: Q93.2
  • OMIM: -
  • UMLS: C0795843
  • MeSH: -
  • GARD: 1325
  • MedDRA: -
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