title: Tetrasomy 9p mosaicism associated with a normal phenotype in two cases.
abstract: Tetrasomy 9p is a rare chromosomal syndrome and about 30% of known cases exhibit mosaicism. Approximately 50 of the reported cases with tetrasomy 9p mosaicism show a characteristic facial appearance, growth failure, and developmental delay. However, 3 patients with mosaicism for isochromosome 9p and a normal phenotype have also been reported. We report 2 additional cases of clinically normal young females with tetrasomy 9p mosaicism, one of whom also exhibited X chromosome aneuploidy mosaicism leading to an overall of 6 different cell lines. STR analysis performed on this complex mosaic case indicated that the extra isochromosome was of maternal origin while the X chromosome aneuploidy was of paternal origin, indicating a postzygotic event.
authors.affiliation: Eurogenetica S.A., Thessaloniki and Athens, Greece.
authors.forename: I
authors.initials: I
authors.lastname: Papoulidis
authors.forename: M
authors.initials: M
authors.lastname: Kontodiou
authors.forename: M
authors.initials: M
authors.lastname: Tzimina
authors.forename: I
authors.initials: I
authors.lastname: Saitis
authors.forename: A B
authors.initials: AB
authors.lastname: Hamid
authors.forename: E
authors.initials: E
authors.lastname: Klein
authors.forename: N
authors.initials: N
authors.lastname: Kosyakova
authors.forename: U
authors.initials: U
authors.lastname: Kordass
authors.forename: J
authors.initials: J
authors.lastname: Kunz
authors.forename: E
authors.initials: E
authors.lastname: Siomou
authors.forename: P
authors.initials: P
authors.lastname: Nicolaides
authors.forename: S
authors.initials: S
authors.lastname: Orru
authors.forename: L
authors.initials: L
authors.lastname: Thomaidis
authors.forename: T
authors.initials: T
authors.lastname: Liehr
authors.forename: M B
authors.initials: MB
authors.lastname: Petersen
authors.forename: E
authors.initials: E
authors.lastname: Manolakos
mesh_terms: D000328:Adult; D000782:Aneuploidy; D002871:Chromosome Banding; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D041321:Chromosomes, Human, X / Q000235:genetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D009030:Mosaicism; D010641:Phenotype; D011247:Pregnancy; D012729:Sex Chromosome Aberrations; D055815:Young Adult