Author:

Keywords:

Abnormalities, Multiple, Chromosomes, Human, X, Face, Humans, In Situ Hybridization, Fluorescence, Male, Mental Retardation, Microsatellite Repeats, Microtubule-Associated Proteins, Nucleic Acid Hybridization, Pedigree, Sex Chromosome Aberrations, Sex Chromosome Disorders, Transcription Factors, Science & Technology, Life Sciences & Biomedicine, Genetics & Heredity, FG syndrome, X-linked inheritance, X chromosome, FGS5, Xq22.3, X-chromosome duplication, trigonocephaly, MENTAL-RETARDATION, OPITZ-SYNDROME, GENE, AMPLIFICATION, LOCALIZATION, INVERSION, FAMILIES, DELETION, LINKAGE, MID2, Intellectual Disability, 0604 Genetics, 1103 Clinical Sciences, 3105 Genetics, 3202 Clinical sciences

Abstract:

FG syndrome is an X-linked multiple congenital anomalies (MCA) syndrome. It has been mapped to four distinct loci FGS1-4, through linkage analysis (Xq13, Xp22.3, and Xp11.4-p11.3) and based on the breakpoints of an X chromosome inversion (Xq11:Xq28), but so far no gene has been identified. We describe a boy with FG syndrome who has an inherited duplication at band Xq22.3 detected by comparative genomic hybridization microarray (Array-CGH). These duplication maps outside all four loci described so far for FG syndrome, representing therefore a new locus, which we propose to be called FGS5. MID2, a gene closely related to MID1, which is known to be mutated in Opitz G/BBB syndrome, maps within the duplicated segment of our patient. Since FG and Opitz G/BBB syndromes share many manifestations we considered MID2 a candidate gene for FG syndrome. We also discuss the involvement of other potential genes within the duplicated segment and its relationship with clinical symptoms of our patient, as well as the laboratory abnormalities found in his mother, a carrier of the duplication.