Related Experiment Video
Updated: Apr 8, 2026

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation
Published on: January 16, 2019
Genetic variation analysis in a Chinese Maffucci syndrome patient
Objective:
To report on the molecular genetic analysis of a Chinese patient with Maffucci syndrome.
Methods:
Using the genomic DNA extracted from the patient's hemangioma sample, the coding exons and exon/intron splice junctions of the IDH1 and IDH2 genes were amplified by polymerase chain reaction (PCR) and then sequenced. Genomic DNA was extracted from blood and a hemangioma sample from the patient, and also from her mother's blood, for chromosome microarray analysis (CMA) by Affymetrix CytoScan HD array.
Results:
None of the known pathogenic mutations in the whole IDH1 or IDH2 genes was found in the patient's hemangioma sample. CMA detected 40 tumor-specific copy number variations (CNVs), and one copy number neutral loss of heterozygosity (LOH) region. Among the 73 known genes included in the 40 CNV regions, only 2 genes, CHEK2 (604373) located in 22q12.1 and EP300 (602700) located in 22q13.2, were found to be related to tumorigenesis. We did not find any CNVs at the IDH1 and IDH2 loci.
Conclusions:
This is the first molecular genetic analysis report on a Chinese patient with Maffucci syndrome and our data enrich the understanding of the genetic background of Maffucci syndrome in different ethnic groups. The relationship between CHEK2, EP300 and Maffucci syndrome needs to be further explored.
More Related Videos
Related Concept Videos
Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Single Nucleotide Polymorphisms-SNPs
Animal Mitochondrial Genetics
Genetic Variation
Genes exist in different versions called alleles,...
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Principles of Pharmacogenetics: Types of Genetic Variants

