title: Phenotypic variability of distal 22q11.2 copy number abnormalities.
abstract: The availability of microarray technology has led to the recent recognition of copy number abnormalities of distal chromosome 22q11.2 that are distinct from the better-characterized deletions and duplications of the proximal region. This report describes five unrelated individuals with copy number abnormalities affecting distal chromosome 22q11.2. We report on novel phenotypic features including diaphragmatic hernia and uterine didelphys associated with the distal microdeletion syndrome; and frontomedial polymicrogyria and callosal agenesis associated with the distal microduplication syndrome. We describe the third distal chromosome 22q11.2 microdeletion patient with Goldenhar syndrome. Patients with distal chromosome 22q11.2 copy number abnormalities exhibit inter- and intra-familial phenotypic variability, and challenge our ability to draw meaningful genotype-phenotype correlations.
authors.affiliation: Genetic Health Services Victoria, Melbourne, Australia. tiong.tan@ghsv.org.au
authors.forename: Tiong Yang
authors.initials: TY
authors.lastname: Tan
authors.forename: Amanda
authors.initials: A
authors.lastname: Collins
authors.forename: Paul A
authors.initials: PA
authors.lastname: James
authors.forename: George
authors.initials: G
authors.lastname: McGillivray
authors.forename: Zornitza
authors.initials: Z
authors.lastname: Stark
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Gordon
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Leventer
authors.forename: Kate
authors.initials: K
authors.lastname: Pope
authors.forename: Robin
authors.initials: R
authors.lastname: Forbes
authors.forename: John A
authors.initials: JA
authors.lastname: Crolla
authors.forename: Devika
authors.initials: D
authors.lastname: Ganesamoorthy
authors.forename: Trent
authors.initials: T
authors.lastname: Burgess
authors.forename: Damien L
authors.initials: DL
authors.lastname: Bruno
authors.forename: Howard R
authors.initials: HR
authors.lastname: Slater
authors.forename: Peter G
authors.initials: PG
authors.lastname: Farlie
authors.forename: David J
authors.initials: DJ
authors.lastname: Amor
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D056915:DNA Copy Number Variations / Q000235:genetics*; D005260:Female; D056726:Genetic Association Studies; D006053:Goldenhar Syndrome / Q000235:genetics; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010641:Phenotype; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D055815:Young Adult