Table 2

Classification of small ring chromosomes 1 and relationship to phenotype

Patient referenceSex% r(1)De novoAscertainmentPhenotype
(1) 1q12 heterochromatin
Case 1, ref 10F25YMCAND, del(18)(q22) also present
Case 17, refs 12 and 13 M90NDAdult patient with CGLNormal
Case 1, ref 14 M100YPNDNormal
(2) 1q12 heterochromatin and euchromatin
Patient D, this reportF15YMinor dysmorphism, protruding tongue,
‚ÄÉheart murmur
Minor dysmorphism, VSD
Case 1, ref 15F22YPNDNormal
(3) Euchromatin, 1q12 heterochromatin absent
Patient A, this reportM30YDevelopmental delay, minor dysmorphismIntellectual disability, minor dysmorphism
Patient B, this reportM30YDevelopmental delay, diarrhoeaIntellectual disability, minor dysmorphism
Patient C, this reportM70YLanguage delay, dysmorphic featuresMinor dysmorphism, lean build
Case 1, ref11 M20YDevelopmental delay, dysmorphismDevelopmental delay, minor
  • F: female, M: male, ND: not determined.

  • PND: prenatal diagnosis, MCA: multiple congenital abnormalities.