Detection of 9p partial trisomy using array-based comparative genomic hybridization / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect chromosomal aberrations in a child with developmental delay and speech and language disorders in order to explore the underlying genetic causes of congenital malformation, and to investigate the feasibility of array-based comparative genomic hybridization (array-CGH) for molecular genetic diagnosis.</p><p><b>METHODS</b>G-banding and array-CGH were applied to characterize the genetic abnormality in the three family members.</p><p><b>RESULTS</b>G-banding analysis revealed the affected child and the healthy mother are both carriers of inv(9)(p13q13), while the child has carried a chromosome fragment derived from chromosome 13. Array-CGH analysis indicated the derivative chromosome fragment has originated from 9p with breakpoints at around 9p13.1-p24.3.</p><p><b>CONCLUSION</b>Trisomy 9p13.1-p24.3 may be the cause of congenital malformation in the child. For its high resolution and high accuracy, array-CGH is a powerful tool for genetic analysis.</p>

Cytogenetic analysis of a complex chromosomal imbalance 14q+ in a fetus featuring multiple congenital defects / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze chromosomal imbalance in a fetus presenting with congenital heart disease and mild lateral ventriculomegaly, and to investigate the correlation between genotype and phenotype. The etiology of the fetal congenital diseases was determined, and the feasibility of array-based comparative genomic hybridization (array-CGH) application in molecular cytogenetic diagnosis was evaluated.</p><p><b>METHODS</b>Following conventional G-banding analysis, array-based comparative genomic hybridization (array-CGH) was applied to delineate the precise location and size of genomic imbalance.</p><p><b>RESULTS</b>A de novo 46, XY, -14, +der14(q31)? karyotype was identified in the fetus by G-banding analysis. Array-CGH has verified the chromosomal imbalance to be 46, XY, -14, +der(12; 14) (p13; q32.33)del(14) (q32.33→ qter).</p><p><b>CONCLUSION</b>del(14)(q32.33→ qter) is probably the predominant cause of the fetal congenital disease. For its high resolution and accuracy, array-CGH has provided a powerful tool for prenatal diagnosis and genetic counseling.</p>

Array-based comparative genomic hybridization detection of copy number variations in a fetus with hypoplastic left-heart syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the copy number variations (CNVs) of a fetus with hypoplastic left-heart syndrome, and to assess the value of array-based comparative genomic hybridization (array-CGH) for molecular cytogenetic diagnosis.</p><p><b>METHODS</b>The whole genome of a fetus with normal karyotype by G-banding was scanned and analyzed by array-CGH, and the CNVs was confirmed by multiplex ligation-dependent probe amplification (MLPA).</p><p><b>RESULTS</b>Two submicroscopic CNVs [del(11)(q24.1-ter)(121951443-134449216, -12.50 Mb),dup(15)(q26.3)(96889082-100215359, -3.33 Mb)] were identified and mapped by array-CGH. MLPA test confirmed both CNVs.</p><p><b>CONCLUSION</b>Del (11) (q24.1-ter) may contribute to hypoplastic left-heart syndrome of the fetus. For its high-resolution and high-accuracy, array-CGH has provided a powerful tool for detection of genomic imbalance.</p>

Prenatal genetic study of fetuses with congenital heart diseases / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the genetic abnormalities of fetuses with congenital heart diseases (CHD), and to provide guidance for the management of pregnancy and genetic counseling.</p><p><b>METHODS</b>Eighty-one fetuses with CHD detected by fetal echocardiography were analyzed by karyotyping after amniocentesis, cordocentesis or chorionic sampling. Then 22q11.2 deletion/duplication was detected by a competitive fluorescent multiplex short tandem repeat assay in 47 CHD fetuses without chromosomal abnormalities. With fluorescence in situ hybridization (FISH) using LSI dual color DNA probe, the deletion/duplication status was confirmed.</p><p><b>RESULTS</b>Thirty-four of 81 CHD fetuses had chromosomal anomalies, and 1 of the 47 CHD fetuses without chromosomal anomalies had duplication at chromosome 22q11. The incidence of aneuploidy associated CHD was 43.2%. The rate of chromosomal anomalies is higher in the cases associated with extra-cardiac anomalies than in that with isolated CHD (64.5% versus 28.0%). In the 35 fetuses with chromosomal abnormalities, 19 (54.3%) were trisomy 18.</p><p><b>CONCLUSION</b>Chromosomal abnormalities occurred in 43.2% of CHD cases and trisomy 18 is the most common aneuploidy. The likelihood of chromosomal anomaly increases when there is extracardiac involvement. Testing for the 22q11.2 microdeletion/duplication is recommended in all CHD fetuses without chromosomal anomalies. It is important for the further management of pregnancy and genetic counseling.</p>