title: Clinical findings and cytogenetic analysis of small supernumerary ring chromosomes 7: report of two new cases.
abstract: Two new patients, mosaic for a small supernumerary ring chromosome 7 are described. There are only seven published reported concerning supernumerary ring chromosome 7 and we reviewed the previously reported cases in an attempt to establish genotype-phenotype correlations, which are particularly important for genetic counselling and clinical genetics. Our first case was a 20 months old girl who was referred for a mild motor developmental delay, an asymmetric facial appearance, a plagiocephaly and a short nose with anteverted nostrils. Our second case was a 9 years old boy who was referred for a IQ at the lower end of the normal range (? 80), obesity, hyperactivity and some dysmorphic features including hypertelorism and down slanting palpebral fissures. In both cases, chromosome analysis after G and R banding and FISH showed a small ring chromosome 7 in respectively 76% and 50% of consecutively scored metaphases. Both ring chromosomes were labelled by FISH using the Williams Syndrome locus probe (Elastin Gene D7S486). Comparison between these two cases and previously published cases allowed to delineate frequent clinical findings. A mild mental retardation was found in the majority of patients. which is an important data for genetic counselling.
authors.affiliation: Service d'Histologie, Biologie de la Reproduction et Cytogénétique (UPMC-EA 1533), Hôpital Tenon (AP-HP), 75020 Paris, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Chantot-Bastaraud
authors.forename: Christine
authors.initials: C
authors.lastname: Muti
authors.forename: Eva
authors.initials: E
authors.lastname: Pipiras
authors.forename: Marie Claude
authors.initials: MC
authors.lastname: Routon
authors.forename: Anne
authors.initials: A
authors.lastname: Roubergue
authors.forename: Lydie
authors.initials: L
authors.lastname: Burglen
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Siffroi
authors.forename: Brigitte
authors.initials: B
authors.lastname: Simon-Bouy
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D002648:Child; D002871:Chromosome Banding; D025063:Chromosome Disorders / Q000235:genetics*; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics / Q000648:ultrastructure*; D005145:Face / Q000002:abnormalities; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D009765:Obesity / Q000235:genetics; D010641:Phenotype; D011595:Psychomotor Agitation / Q000235:genetics; D012303:Ring Chromosomes; D014314:Trisomy