De novo supernumerary ring chromosome 7: First report of a non-mosaic patient and review of the literature

Gopalrao V.N. Velagaleti, S. M. Jalal, M. K. Kukolich, L. H. Lockhart, V. S. Tonk

Research output: Contribution to journalArticle

16 Scopus citations


The present authors report the case of a 12-year-old-boy with a de novo, non-mosaic supernumerary ring chromosome 7 associated with significant developmental delay and speech difficulty. A review of the literature identified a total of 18 cases with ring chromosomes 7 who can be classified into two groups: (1) patients with a cell line that has 47 chromosomes with a small supernumerary ring chromosome 7 resulting in partial trisomy; and (2) individuals had a cell line with a large ring chromosome replacing one of the normal chromosomes 7 resulting in partial monosomy. A comparison of clinical features in the two groups of patients showed several common features such as growth and mental retardation, and facial dysmorphism, including, ear and eye anomalies. However, patients with partial trisomy have speech difficulty as a distinguishing feature, while patients with partial monosomy have skin lesions as a cardinal feature. All the published cases of ring chromosome 7, irrespective whether they are supernumerary or normal modal number, are mosaics except for one. The present subject is the first case of a de novo, non-mosaic supernumerary ring chromosome 7.

Original languageEnglish (US)
Pages (from-to)202-206
Number of pages5
JournalClinical Genetics
Issue number3
StatePublished - Mar 1 2002



  • Dysmorphic facies
  • Fluorescence in situ hybridization
  • Ring chromosome 7
  • Skin lesions
  • Speech difficulty

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)

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