Characterization of a de novo sSMC 17 detected in a girl with developmental delay and dysmorphic features.
BACKGROUND
The majority of small supernumerary marker chromosome cases arisede novoand their frequency in newborns is 0.04%. We report on a girl with developmental delay and dysmorphic features with a non-mosaicde novosSMC that originated from the pericentric region of q arm in chromosome 17.


METHODS
The girl presented with developmental delay, speech delay, myopia, mild muscle hypotonia, hypoplasia of orbicular muscle, poor concentration, and hyperactivity. Main dysmorphic features included: round face, microstomia, small chin, down-slanting palpebral fissures and small lobules of both ears. At present, her developmental abilities are still delayed for her chronological age but she is making evident progress with speech. A postnatal array comparative genomic hybridization showed a 2.31 Mb genomic gain indicating microduplication derived from pericentric regions q11.1 and q11.2 of chromosome 17. Additional conventional cytogenetic analysis from peripheral blood characterized the karyotype as 47,XX,+mar in a non-mosaic form. The location of microduplication was confirmed with fluorescencein situhybridization.


CONCLUSIONS
The proband's microduplication encompassed approximately 40 annotated genes, several of which have been associated with phenotypic characteristics of the proband. This is the first report of sSMC 17 including this particular chromosomal region in non-mosaic form.
University Children's Hospital, University Medical Centre Ljubljana, Unit for Special Laboratory Diagnostic, Vrazov trg 1, SI-1525 Ljubljana, Slovenia.
Lana
L
Stavber
Department of Pediatric Endocrinology, Diabetes and Metabolic Diseases, University Children's Hospital, UMC, Ljubljana, Slovenia.
Sara
S
Bertok
University Children's Hospital, University Medical Centre Ljubljana, Unit for Special Laboratory Diagnostic, Vrazov trg 1, SI-1525 Ljubljana, Slovenia.
Jernej
J
Kovač
Clinical Institute of Medical Genetic, UMC, Ljubljana, Slovenia.
Marija
M
Volk
Clinical Institute of Medical Genetic, UMC, Ljubljana, Slovenia.
Luca
L
Lovrečić
Department of Pediatric Endocrinology, Diabetes and Metabolic Diseases, University Children's Hospital, UMC, Ljubljana, Slovenia.|Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
Tadej
T
Battelino
University Children's Hospital, University Medical Centre Ljubljana, Unit for Special Laboratory Diagnostic, Vrazov trg 1, SI-1525 Ljubljana, Slovenia.
Tinka
T
Hovnik
Developmental delay; Dysmorphic features; Small supernumerary marker chromosome; Speech delay; fluorescence in situ hybridization