title: A de novo 4q34 interstitial deletion of at least 9.3 Mb with no discernible phenotypic effect.
abstract: Cytogenetically visible imbalances without phenotypic effect are still rare despite the extent of large-scale copy number variation in the normal population revealed by array CGH. Here we report on a phenotypically normal 30-year-old female with a de novo, cytogenetically visible, interstitial deletion of band 4q34. She was referred following three successive miscarriages, one of which was an intra-uterine death with subendocardial fibroelastosis and dilated cardiomyopathy. There was no other notable medical or family history, she was of normal intelligence and had no dysmorphic features. FISH and Array CGH with a customized 1 Mb BAC array showed that the deletion is a minimum of 9.3 and a maximum of 10.7 Mb in size, between approximately 173 Mb in 4q34.1 and approximately 182 Mb in 4q34.3. The deletion contains only 23 known coding genes giving a low average gene density of approximately 2 genes/Mb. This case further illustrates that (1) sizeable imbalances can be associated with apparent phenotypic normality, (2) gene density is a better guide to possible phenotypic consequences than aberration size, and (3) it is not always safe to assume that de novo imbalances will be causal.
authors.affiliation: Wessex Regional Genetics Laboratory, Salisbury NHS Foundation Trust, Salisbury District Hospital, Salisbury, United Kingdom. mark.bateman@salisbury.nhs.uk
authors.forename: Mark S
authors.initials: MS
authors.lastname: Bateman
authors.forename: Sarju G
authors.initials: SG
authors.lastname: Mehta
authors.forename: Lionel
authors.initials: L
authors.lastname: Willatt
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Selkirk
authors.forename: Clare
authors.initials: C
authors.lastname: Bedwell
authors.forename: Simon
authors.initials: S
authors.lastname: Zwolinski
authors.forename: Leeanne
authors.initials: L
authors.lastname: Sparnon
authors.forename: Ingrid
authors.initials: I
authors.lastname: Simonic
authors.forename: Kristin
authors.initials: K
authors.lastname: Abbott
authors.forename: John C K
authors.initials: JC
authors.lastname: Barber
mesh_terms: D000328:Adult; D020029:Base Pairing / Q000235:genetics*; D002648:Child; D002871:Chromosome Banding; D019457:Chromosome Breakage; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D010641:Phenotype