Microduplication 22q11.2, an emerging syndrome: clinical, cytogenetic, and molecular analysis of thirteen patients.
Am J Hum Genet
; 73(5): 1027-40, 2003 Nov.
Article
in En
| MEDLINE
| ID: mdl-14526392
ABSTRACT
Chromosome 22, particularly band 22q11.2, is predisposed to rearrangements due to misalignments of low-copy repeats (LCRs). DiGeorge/velocardiofacial syndrome (DG/VCFS) is a common disorder resulting from microdeletion within the same band. Although both deletion and duplication are expected to occur in equal proportions as reciprocal events caused by LCR-mediated rearrangements, very few microduplications have been identified. We have identified 13 cases of microduplication 22q11.2, primarily by interphase fluorescence in situ hybridization (FISH). The size of the duplications, determined by FISH probes from bacterial artificial chromosomes and P(1) artificial chromosomes, range from 3-4 Mb to 6 Mb, and the exchange points seem to involve an LCR. Molecular analysis based on 15 short tandem repeats confirmed the size of the duplications and indicated that at least 1 of 15 loci has three alleles present. The patients' phenotypes ranged from mild to severe, sharing a tendency for velopharyngeal insufficiency with DG/VCFS but having other distinctive characteristics, as well. Although the present series of patients was ascertained because of some overlapping features with DG/VCF syndromes, the microduplication of 22q11.2 appears to be a new syndrome.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Abnormalities, Multiple
/
Chromosomes, Human, Pair 22
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Gene Duplication
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Cytogenetic Analysis
Type of study:
Prognostic_studies
Limits:
Adolescent
/
Child
/
Child, preschool
/
Female
/
Humans
/
Infant
/
Male
/
Newborn
Language:
En
Journal:
Am J Hum Genet
Year:
2003
Document type:
Article
Affiliation country:
United States