Tetrasomy 15q26: a distinct syndrome or Shprintzen-Goldberg syndrome phenocopy?
OBJECTIVE
The aim of this study was to characterize the clinical phenotype of patients with tetrasomy of the distal 15q chromosome in the form of a neocentric marker chromosome and to evaluate whether the phenotype represents a new clinical syndrome or is a phenocopy of Shprintzen-Goldberg syndrome.


METHODS
We carried out comprehensive clinical evaluation of four patients who were identified with a supernumerary marker chromosome. The marker chromosome was characterized by G-banding, fluorescence in situ hybridization, single nucleotide polymorphism oligonucleotide microarray analysis, and immunofluorescence with antibodies to centromere protein C.


RESULTS
The marker chromosomes were categorized as being neocentric with all showing tetrasomy for regions distal to 15q25 and the common region of overlap being 15q26→qter.


CONCLUSIONS
Tetrasomy of 15q26 likely results in a distinct syndrome as the patients with tetrasomy 15q26 share a strikingly more consistent phenotype than do the patients with Shprintzen-Goldberg syndrome, who show remarkable clinical variation.
Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA. BL2185@Columbia.edu
Brynn
B
Levy
David
D
Tegay
Peter
P
Papenhausen
James
J
Tepperberg
Odelia
O
Nahum
Tammy
T
Tsuchida
Beth A
BA
Pletcher
Leena
L
Ala-Kokko
Stuart
S
Baker
Barbara
B
Frederick
Kurt
K
Hirschhorn
Peter
P
Warburton
Alan
A
Shanske
D000328:Adult; D054119:Arachnodactyly / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics; D002871:Chromosome Banding; D002884:Chromosomes, Human, Pair 15; D003398:Craniosynostoses / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D005260:Female; D005819:Genetic Markers; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D008382:Marfan Syndrome / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D010641:Phenotype; D013577:Syndrome; D058670:Tetrasomy / Q000235:genetics* / Q000473:pathology
D002868:Chromosomal Proteins, Non-Histone; D005819:Genetic Markers; C060905:centromere protein C