ABSTRACT
In about 50 percent of first trimester spontaneous abortion the cause remains undetermined after standard cytogenetic investigation. We evaluated the usefulness of array-CGH in diagnosing chromosome abnormalities in products of conception from first trimester spontaneous abortions. Cell culture was carried out in short- and long-term cultures of 54 specimens and cytogenetic analysis was successful in 49 of them. Cytogenetic abnormalities (numerical and structural) were detected in 22 (44.89 percent) specimens. Subsequent, array-CGH based on large insert clones spaced at ~1 Mb intervals over the whole genome was used in 17 cases with normal G-banding karyotype. This revealed chromosome aneuplodies in three additional cases, giving a final total of 51 percent cases in which an abnormal karyotype was detected. In keeping with other recently published works, this study shows that array-CGH detects abnormalities in a further ~10 percent of spontaneous abortion specimens considered to be normal using standard cytogenetic methods. As such, array-CGH technique may present a suitable complementary test to cytogenetic analysis in cases with a normal karyotype.
ABSTRACT
Chromosomal rearrangements involving partial deletion of the short arm of chromosome 4 and partial duplication of the short arm of chromosome 8 have been described both in Pitt-Rogers-Danks syndrome (PRDS) and Wolf-Hirschhorn syndrome (WHS), the former being considered a milder phenotype of the latter. We describe a patient with partial deletion of chromosome 4 and partial duplication of chromosome 8 documented by array-comparative genomic hybridization (Array-CGH). In addition to the typical features of PRDS, the patient exhibited some clinical signs (genital hypoplasia, radioulnar synostosis and mesomelic limb shortness) infrequently, or never previously, reported in PRDS. These findings broaden the spectrum of anomalies generally associated with these syndromes.
Subject(s)
Abnormalities, Multiple/pathology , Chromosome Deletion , Chromosomes, Human, Pair 22 , Heredity , Urogenital Abnormalities/pathology , Adolescent , DNA/analysis , DNA/genetics , Female , Genetic Markers , Humans , Nucleic Acid Hybridization , Oligonucleotide Array Sequence Analysis , Physical Chromosome Mapping , Polymorphism, Single Nucleotide , Polymorphism, Single-Stranded Conformational , Proto-Oncogene Proteins/genetics , Radiography , Receptors, Retinoic Acid/genetics , Retinoid X Receptor alpha/genetics , Spine/abnormalities , Spine/diagnostic imaging , Syndrome , Ultrasonography , Urogenital Abnormalities/diagnosis , Urogenital Abnormalities/diagnostic imaging , Wnt Proteins/genetics , Wnt4 Protein , Retinoic Acid Receptor gammaABSTRACT
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.
Subject(s)
Abnormalities, Multiple/genetics , Chromosomes, Human, X/genetics , Face/abnormalities , Intellectual Disability/genetics , Microtubule-Associated Proteins/genetics , Sex Chromosome Aberrations , Sex Chromosome Disorders/pathology , Transcription Factors/genetics , Humans , In Situ Hybridization, Fluorescence , Male , Microsatellite Repeats/genetics , Nucleic Acid Hybridization/genetics , Pedigree , Sex Chromosome Disorders/geneticsABSTRACT
Three de novo short-arm duplications of chromosome 9 were investigated by fluorescence in situ hybridization (FISH) and genotyping of microsatellite loci with the aim of disclosing their mechanisms of origin. Two of these duplications were identified as direct and one as an inverted duplication, and they comprised nearly the entire 9p. In the two dirdup(9p), the distal breakpoints were mapped to subtelomeric sequences, whereas the proximal break boundaries were defined by pericentromeric sequences. The maternal origin of both duplications was demonstrated, and the presence of three different alleles in distal loci indicated that these rearrangements must have occurred prezygotically. In the invdup(9p), the proximal breakpoint was mapped at the alphoid sequences, which were partially duplicated on the tip of the rearranged 9p; subtelomeric and telomeric sequences were not detected, allowing the distal breakpoint to be mapped proximally to subtelomeric sequences. Genotyping of microsatellite loci allowed us to conclude that this invdup(9p) chromosome had a paternal origin. Homozygosity throughout the duplicated segment pointed to its probable postzygotic formation. Chromatid rearrangements appeared to have originated these 9p duplications, involving pericentromeric and subtelomeric sequences. These rearrangements might have been the result of recombination events between homologous repeats in these segments.
