Detection of a patient with ring chromosome 15 by low-coverage massively parallel copy number variation sequencing / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the genetic cause for a child with developmental delay.</p><p><b>METHODS</b>The karotypes of the child and her parents were analyzed with G-banding analysis. Their genome DNA was analyzed with low-coverage massively parallel copy number variation sequencing (CNV-seq) and verified by single nucleotide polymorphism array (SNP-array).</p><p><b>RESULTS</b>The karyotype of the child was ascertained as 46,XX,r(15)(p13q26.3), while both parents showed a normal karyotype. CNV-seq and SNP-array have identified a de novo 15q26.2-q26.3 deletion in the child with a size of approximately 3.60 Mb.</p><p><b>CONCLUSION</b>The abnormal phenotype of the patient carrying the ring chromosome 15 may be attributed to the presence of the 15q26.2-q26.3 microdeletion. The deletion and haploinsufficiency of the IGF1R gene probably underlie the main clinical features of the patient.</p>

Genetic analysis of a mental retardation patient with a rare karyotype involving complex rearrangements of five chromosomes / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the genetic cause of a female patient with severe mental retardation and a history of adverse pregnancy.</p><p><b>METHODS</b>The patient was subjected to G-banded chromosome analysis and single nucleotide polymorphism array (SNP-array) assaying. The correlation between genomic variations and the phenotype was explored.</p><p><b>RESULTS</b>The patient was found to have a complex chromosome rearrangement involving 5 chromosomes. The karyotypes of her parents were both normal. SNP-array assay has identified a 1.6 Mb microdeletion at chromosome 15q21.3 which involved 15 RefSeq genes and a 0.5 Mb microdeletion at 5q21.1 which involved one RefSeq gene.</p><p><b>CONCLUSION</b>The microdeletions, which involved TCF12, ADMA10 and AQP9 genes, probably underlie the mental retardation shown by the patient.</p>

Phenotypic and genetic analysis of a child featuring multiple malformations due to chromosome 18p deletion / 中华医学遗传学杂志

OBJECTIVE To analyze a neonate with multiple malformations and to correlate its genotype with phenotype. METHODS The karotypes of the child and her parents were subjected to G-banding chromosome analysis, and array comparative genomic hybridization (array-CGH) was used for fine mapping of the aberrant region. RESULTS The karyotype of the child was ascertained as 46,XX,del(18)(p11.2). Array CGH has identified a 9.8 Mb deletion at 18p11.32-p11.22. The patient has presented features such as holoprosencephaly, choanal atresia, heart defect, and craniofacial dysmorphisms. CONCLUSION The de novo 18p deletion probably underlies the main clinical manifestations of the child.