Identification of familial and de novo microduplications of 22q11.21-q11.23 distal to the 22q11.21 microdeletion syndrome region.
Hum Mol Genet
; 18(8): 1377-83, 2009 Apr 15.
Article
in En
| MEDLINE
| ID: mdl-19193630
ABSTRACT
Deletions of the 22q11.2 region distal to the 22q11.21 microdeletion syndrome region have recently been described in individuals with mental retardation and congenital anomalies. Because these deletions are mediated by low-copy repeats (LCRs), located distal to the 22q11.21 DiGeorge/velocardiofacial microdeletion region, duplications are predicted to occur with a frequency equal to the deletion. However, few microduplications of this region have been reported. We report the identification of 18 individuals with microduplications of 22q11.21-q11.23. The duplication boundaries for all individuals are within LCRs distal to the DiGeorge/velocardiofacial microdeletion region. Clinical records for nine subjects reveal shared characteristics, but also several examples of contradicting clinical features (e.g. macrocephaly versus microcephaly and upslanting versus downslanting palpebral fissures). Of 12 cases for whom parental DNA samples were available for testing, one is de novo and 11 inherited the microduplication from a parent, three of whom reportedly have learning problems or developmental delay. The variable phenotypes and preponderance of familial cases obfuscate the clinical relevance of the molecular data and emphasize the need for careful parental assessments and clinical correlations.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
DiGeorge Syndrome
Type of study:
Diagnostic_studies
/
Prognostic_studies
Limits:
Child
/
Female
/
Humans
/
Male
Language:
En
Journal:
Hum Mol Genet
Journal subject:
BIOLOGIA MOLECULAR
/
GENETICA MEDICA
Year:
2009
Document type:
Article
Affiliation country:
United States