Copy number imbalances detected with a BAC-based array comparative genomic hybridization platform in congenital diaphragmatic hernia fetuses.

Congenital diaphragmatic hernia (CDH) is a phenotypically and genetically heterogeneous disorder, with a complex inheritance pattern. Structural abnormalities of almost all chromosomes have been described in association with CDH. We made a molecular analysis through array comparative genomic hybridization (array CGH) of a group of fetuses with prenatal ultrasound diagnosis of CDH and normal G-banded karyotypes. A whole genome BAC-array CGH, composed of approximately 5000 BAC clones, was carried out on blood samples from fetuses with prenatal ultrasound diagnosis of CDH and a normal karyotype (500-band level). All potential cytogenetic alterations detected on the arrays were reported. The array CGH analysis showed copy number gains and losses in 10 of 12 cases. Eighty-five clones showed genomic imbalances, and 29 clones displayed described copy number variations. We identified a recurrent gain in 17q12 in two of 12 cases, which has not been previously described. Our results may contribute to determining the effectiveness and applicability of array CGH for prenatal diagnosis purposes, and also to elucidate the submicroscopic genomic instability of CDH fetuses.

Prenatal diagnosis of a partial trisomy 13q (q14-->qter): phenotype, cytogenetics and molecular characterization by spectral karyotyping and array comparative genomic hybridization.

Partial trisomy 13q is an uncommon chromosomal abnormality with variable phenotypic expression. We report prenatal diagnosis of partial trisomy 13q in a fetus with partial agenesis of the cerebellar vermis, partial agenesis of the corpus callosum, hydrops and polyhydramnios. G-banding karyotyping, spectral karyotyping and array comparative genomic hybridization (aCGH) analysis of fetal blood were performed. Cytogenetic analysis of fetal blood displayed 46,XX,add(4)(q28). The parental karyotypes were normal. A girl was delivered at 34 weeks gestation; she died within 2 h. Autopsy confirmed all the prenatal findings and also showed agenesis of the diaphragm. Spectral karyotyping identified the additional material's origin as chromosome 13. aCGH was carried out and showed amplification of distal regions of the long arm of chromosome 13 from region 13q14 to qter. This is the first report of a fetus with molecular characterization of a partial trisomy 13q (q14-->qter), present as a de novo unbalanced translocation at chromosome 4q. This case demonstrates the usefulness of molecular characterization of malformed fetuses for prenatal diagnosis and counseling.

Outcome of fetal urinary tract anomalies associated with multiple malformations and chromosomal abnormalities.

The purpose of this study was to identify prognostic factors and describe the outcome of prenatally detected renal anomalies associated with multiple malformations and chromosomal defects. Forty-one fetuses were included in the analysis. Prenatal ultrasound reports, neonatal records and autopsy information were retrospectively reviewed. Prognostic factors associated with fetal echography and clinical and laboratory findings on admission were studied. Data were analyzed by univariate analysis in which variables associated with adverse outcome were identified by the Chi-square test or Fisher exact test. The abnormalities associated with renal anomalies were divided into three groups: chromosomal defects (21%), previously described syndromes and conditions (24%), and new sporadic conditions (55%). Of 41 children admitted, 30 (76%) died during the perinatal period. The presence of oligohydramnios was significantly associated with an adverse outcome (OR=11, p=0.05). Male gender was a protective factor against death during the perinatal period (OR=0.11, p=0.01). In conclusion, prenatally detected renal anomalies associated with multiple malformations and chromosomal defects had a poor prognosis. The presence of oligohydramnios increased the risk of death, and male gender had a protective role against poor outcome.