Characterization of the phenotype and definition of the deletion in a new patient with ring chromosome 22

R. Battini, A. Battaglia, V. Bertini, G. Cioni, B. Parrini, E. Rapalini, P. Simi, F. Tinelli, A. Valetto

Research output: Contribution to journalArticle

Abstract

The clinical phenotype of patients with ring chromosome 22 includes mental retardation with severe language impairment, hypotonia, and dysmorphic facial features. In recent years an increasing number of patients with microscopic as well as cryptic terminal deletion involving band 22q13 have been described and their phenotype shows clinical features overlapping with patients with ring chromosome 22. Loss of DNA in the 22q13.3 region may lead to a clinically recognizable syndrome named "22q13.3 deletion syndrome." We report a patient with a ring chromosome 22 who has hypotonia, profound mental retardation, language impairment, dysmorphic features, and behavioral disorders. To check if the critical region responsible for "22q13.3 deletion syndrome" was absent in this ring, a fluorescent in situ hybridization (FISH) analysis using a probe corresponding to the ARSA locus was performed. In our patient, only one ARSA signal could be detected, indicating that the deletion encompassed the critical 22q13.3 region. A more detailed analysis of the deletion extent then was performed using a panel of fluorescent probes located within 22q13. These experiments allowed the identification of the breakpoint between CTA-299D3 and RP5-925J7 probe, located in 22q13.32. Deletion extent could be estimated to be about 2.5 Mb, and this larger deletion may explain the severity of clinical features observed in our patient.

Original languageEnglish
Pages (from-to)196-199
Number of pages4
JournalAmerican Journal of Medical Genetics
Volume130 A
Issue number2
DOIs
Publication statusPublished - Oct 1 2004

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Keywords

  • 22q13.3 deletion syndrome
  • Chromosome aberration
  • Language impairment
  • Multiple congenital anomalies/mental retardation syndrome
  • Ring chromosome 22 [r(22)]

ASJC Scopus subject areas

  • Genetics(clinical)

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