The Spectrum of Cytogenomic Abnormalities in Patients with Developmental Delay and Intellectual Disabilities

Peining Li, Fang Xu, Wei Shu


Current clinical cytogenomics laboratory uses array comparative genomic hybridization (aCGH) or single nucleotide polymorphism (SNP) chip as first-tier test supplemented with routine karyotyping and fluorescent in situ hybridization (FISH) for patients with developmental delay (DD), intellectual disability (ID), multiple congenital anomalies (MCA) and autistic spectrum disorders (ASD). A spectrum of cytogenomic abnormalities including numerical chromosomal abnormalities, unbalanced and balanced structural and cryptic rearrangements, and recurrent genomic disorders have been detected 10~20% of patients with DD/ID/MCA/ASD and collectively present in approximately 0.8% of a general population. The characterization of genomic coordinates and gene contents for these abnormalities has enabled accurate mapping of candidate genes and correlating genotypes with phenotypes and thus more informative genetic counseling. Future application of WGS will expand this spectrum of cytogenomic abnormalities by including complex and cryptic structural variants. Further delineation of molecular mechanisms of these cytogenomic abnormalities and development of novel therapeutic approaches will ultimately lead to disease-specific personalized management and precision treatment. 


array comparative genomic hybridization (aCGH), whole-genome sequencing (WGS), chromosomal abnormalities, copy number variant (CNV), Cryptic rearrangements, developmental delay (DD), intellectual disability (ID)

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