title: Characterization of sSMC by FISH and molecular techniques.
abstract: Small supernumerary marker chromosome (sSMC) is a structurally altered additional chromosome that may not be explicitly clarified by conventional karyotyping alone. About one third of sSMC carriers have abnormal phenotypes and its clinical correlation is difficult, especially in prenatal studies. The present study was aimed at characterizing 19 sSMC identified in 15 patients with dysmorphic features with or without multiple congenital anomalies, conspicuous family history, short stature and/or ambiguous genitalia. All the sSMC were primarily identified by routine cytogenetics studies (performed with banding techniques) from peripheral blood except in one patient, where amniotic fluid was used. All sSMCs were further characterized by array-CGH (using 44 K oligonucleotide probe) and/or fluorescence in situ hybridization (FISH) using multicolor banding (MCB), centromere specific multicolor FISH (cenM-FISH), subcentromere-specific multicolor FISH (subcenM-FISH), micro-dissection and/or reverse FISH. This report demonstrates the worth of advanced molecular (cyto)genetic techniques in characterizing sSMC, their utility in genotype-phenotype correlation and risk of clinical presentation.
authors.affiliation: Institute of Human Genetics, Foundation for Research In Genetics and Endocrinology, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad 380 015, India. fshethad1@googlemail.com
authors.forename: Frenny
authors.initials: F
authors.lastname: Sheth
authors.forename: Joris
authors.initials: J
authors.lastname: Andrieux
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ewers
authors.forename: Nadezda
authors.initials: N
authors.lastname: Kosyakova
authors.forename: Anja
authors.initials: A
authors.lastname: Weise
authors.forename: Harsh
authors.initials: H
authors.lastname: Sheth
authors.forename: Serge-Pierrick
authors.initials: SP
authors.lastname: Romana
authors.forename: Marc
authors.initials: M
authors.lastname: LeLorc'h
authors.forename: Bruno
authors.initials: B
authors.lastname: Delobel
authors.forename: Olivier
authors.initials: O
authors.lastname: Theisen
authors.forename: Thomas
authors.initials: T
authors.lastname: Liehr
authors.forename: Sheela
authors.initials: S
authors.lastname: Nampoothiri
authors.forename: Jayesh
authors.initials: J
authors.lastname: Sheth
mesh_terms: D002869:Chromosome Aberrations; D002871:Chromosome Banding; D025063:Chromosome Disorders / Q000175:diagnosis / Q000235:genetics*; D055028:Comparative Genomic Hybridization / Q000379:methods*; D005192:Family Health; D005260:Female; D056726:Genetic Association Studies / Q000379:methods; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007621:Karyotyping; D008297:Male; D010375:Pedigree; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity