title: Five cases of supernumerary small ring chromosomes 1: heterogeneity and genotype-phenotype correlation.
abstract: Genetic counselling of patients with small supernumerary ring chromosomes (sSRCs) can be difficult, especially in prenatal testing, due to the complexity in establishing a karyotype-phenotype correlation. In fact, it has been estimated that about 10% of extra ring(1) chromosomes are associated with an unremarkable phenotype. We report on five new cases of extra ring chromosomes(1) manifesting different clinical outcome. One case was familial, segregating from a mother with mosaic karyotype, while the others were de novo. Ring chromosomes were characterised by FISH. In three subjects the involvement of the same euchromatic 1p region was demonstrated. Present observations corroborate previous results and provide some insight into the identification of the harmless ring(1) structures.
authors.affiliation: Ospedale Casa Sollievo della Sofferenza, San Giovanni Rotondo e Istituto CSS-Mendel, Roma, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Bernardini
authors.forename: Anna
authors.initials: A
authors.lastname: Capalbo
authors.forename: Maria Gabriella
authors.initials: MG
authors.lastname: D'Avanzo
authors.forename: Isabella
authors.initials: I
authors.lastname: Torrente
authors.forename: Paola
authors.initials: P
authors.lastname: Grammatico
authors.forename: Domenico
authors.initials: D
authors.lastname: Dell'Edera
authors.forename: Denise Pontes
authors.initials: DP
authors.lastname: Cavalcanti
authors.forename: Antonio
authors.initials: A
authors.lastname: Novelli
authors.forename: Bruno
authors.initials: B
authors.lastname: Dallapiccola
mesh_terms: D002871:Chromosome Banding; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D005260:Female; D005817:Genetic Counseling; D018740:Genetic Heterogeneity; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male; D018895:Microsatellite Repeats; D009030:Mosaicism; D010641:Phenotype; D011247:Pregnancy; D012303:Ring Chromosomes; D024182:Uniparental Disomy
chemical_list: D005819:Genetic Markers