title: X-linked Opitz syndrome: novel mutations in the MID1 gene and redefinition of the clinical spectrum.
abstract: Opitz (or G/BBB) syndrome is a pleiotropic genetic disorder characterized by hypertelorism, hypospadias, and additional midline defects. This syndrome is heterogeneous with an X-linked (XLOS) and an autosomal dominant (ADOS) form. The gene implicated in the XLOS form, MID1, encodes a protein containing a RING-Bbox-Coiled-coil motif belonging to the tripartite motif (TRIM) family. To further clarify the molecular basis of XLOS, we have undertaken mutation analysis of the MID1 gene in patients with Opitz syndrome (OS). We found novel mutations in 11 of 63 male individuals referred to us as sporadic or familial X-linked OS cases. The mutations are scattered throughout the gene, although more are represented in the 3' region. By reviewing all the MID1-mutated OS patients so far described, we confirmed that hypertelorism and hypospadias are the most frequent manifestations, being present in almost every XLOS individual. However, it is clear that laryngo-tracheo-esophageal (LTE) defects are also common anomalies, being manifested by all MID1-mutated male patients. Congenital heart and anal abnormalities are less frequent than reported in literature. In addition, we can include limb defects in the OS clinical synopsis as we found a MID1-mutated patient showing syndactyly. The low frequency of mutations in MID1 and the high variability of the phenotype suggest the involvement of other genes in the OS phenotype.
authors.affiliation: Telethon Institute of Genetics and Medicine, Naples, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: De Falco
authors.forename: Silvia
authors.initials: S
authors.lastname: Cainarca
authors.forename: Grazia
authors.initials: G
authors.lastname: Andolfi
authors.forename: Rosa
authors.initials: R
authors.lastname: Ferrentino
authors.forename: Caterina
authors.initials: C
authors.lastname: Berti
authors.forename: German
authors.initials: G
authors.lastname: Rodríguez Criado
authors.forename: Olaf
authors.initials: O
authors.lastname: Rittinger
authors.forename: Nick
authors.initials: N
authors.lastname: Dennis
authors.forename: Sylvie
authors.initials: S
authors.lastname: Odent
authors.forename: Amit
authors.initials: A
authors.lastname: Rastogi
authors.forename: Jan
authors.initials: J
authors.lastname: Liebelt
authors.forename: David
authors.initials: D
authors.lastname: Chitayat
authors.forename: Robin
authors.initials: R
authors.lastname: Winter
authors.forename: Harindar
authors.initials: H
authors.lastname: Jawanda
authors.forename: Andrea
authors.initials: A
authors.lastname: Ballabio
authors.forename: Brunella
authors.initials: B
authors.lastname: Franco
authors.forename: Germana
authors.initials: G
authors.lastname: Meroni
mesh_terms: D024509:3' Flanking Region; D000015:Abnormalities, Multiple / Q000235:genetics* / Q000473:pathology; D041321:Chromosomes, Human, X / Q000235:genetics*; D004252:DNA Mutational Analysis; D008040:Genetic Linkage; D006801:Humans; D006972:Hypertelorism / Q000235:genetics / Q000473:pathology; D007021:Hypospadias / Q000235:genetics / Q000473:pathology; D007830:Larynx / Q000002:abnormalities; D008297:Male; D009154:Mutation; D010375:Pedigree; D013577:Syndrome