title: Overgrowth and trisomy 15q26.1-qter including the IGF1 receptor gene: report of two families and review of the literature.
abstract: Overgrowth is rarely associated with chromosomal imbalances. Here we report on four children from two unrelated families presenting with overgrowth and a terminal duplication of the long arm of chromosome 15 diagnosed using cytogenetic and FISH studies. In both cases, chromosome analysis of the parents showed a balanced translocation involving 15q26.1-qter. Molecular and cytogenetic studies showed three copies of the insulin-like growth factor 1 receptor (IGF1R) gene. This finding suggests that overgrowth observed in our patients might be causally related to a dosage effect of the IGF1R gene, in contrast to severe growth retardation observed in patients with terminal deletion of 15q. The present observation emphasises the importance of chromosome analysis in patients with overgrowth and mental retardation. Moreover, it further delineates a specific phenotype related to trisomy 15q26.1-qter with macrosomia at birth, overgrowth, macrocephaly and mild developmental delay being the major clinical features.
authors.affiliation: Département de Génétique, Hôpital Necker-Enfants Malades, Paris, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Faivre
authors.forename: Philippe
authors.initials: P
authors.lastname: Gosset
authors.forename: Valérie
authors.initials: V
authors.lastname: Cormier-Daire
authors.forename: Sylvie
authors.initials: S
authors.lastname: Odent
authors.forename: Jeanne
authors.initials: J
authors.lastname: Amiel
authors.forename: Irina
authors.initials: I
authors.lastname: Giurgea
authors.forename: Marie-Cécile
authors.initials: MC
authors.lastname: Nassogne
authors.forename: Laurent
authors.initials: L
authors.lastname: Pasquier
authors.forename: Arnold
authors.initials: A
authors.lastname: Munnich
authors.forename: Serge
authors.initials: S
authors.lastname: Romana
authors.forename: Marguerite
authors.initials: M
authors.lastname: Prieur
authors.forename: Michel
authors.initials: M
authors.lastname: Vekemans
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: De Blois
authors.forename: Catherine
authors.initials: C
authors.lastname: Turleau
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics; D002884:Chromosomes, Human, Pair 15; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D010375:Pedigree; D017526:Receptor, IGF Type 1 / Q000235:genetics*; D014178:Translocation, Genetic; D014314:Trisomy
chemical_list: D017526:Receptor, IGF Type 1