Related Experiment Video
Updated: Jan 21, 2026
Micromanipulation of Chromosomes in Insect Spermatocytes
Published on: October 22, 2018
[Kleefstra syndrome 1 and ring chromosome 9 in a case]
Nan Lyu1, Dongxiao Li, Jingjie Li
1Rehabilitation Center, Children' s Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450003, China. sqing1965@163.com.
Objective:
To analyze the clinical and molecular genetic characteristics of patient with Kleefstra syndrome 1.
Methods:
Clinical data, chromosomal karyotype and whole genome copy number variations (CNVs) of the patient were analyzed.
Results:
The patient was found to have a karyotype of 45,XX,-9[4]/46,XX,r(9)(p24q34)[56]. Whole-genome CNVs detection revealed that she has carried a heterozygous deletion of approximately 670 kb at 9q34.3, which encompassed the entire EHMT1 gene. The region is strongly associated with Kleefstra syndrome (1/9q telomere deletion). In addition, the patient also had heterozygous deletion of 9pter, which may predispose to formation of ring chromosome 9.
Conclusion:
The child was diagnosed with Kleefstra syndrome type 1 in conjunct with ring chromosome 9.
More Related Videos
08:11Quantitative Methods to Study Protein Arginine Methyltransferase 1-9 Activity in Cells
Published on: August 7, 2021
09:39Generation of Induced Pluripotent Stem Cells from Turner Syndrome 45XO Fetal Cells for Downstream Modelling of Neurological Deficits Associated with the Syndrome
Published on: December 4, 2021
Related Concept Videos
02:04Polytene Chromosomes
02:04Polytene Chromosomes
02:40Chromosome Structure
The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division.
Telomeres consist of non-coding repetitive nucleotide...
02:40Chromosome Structure
01:51Lampbrush Chromosomes
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops...
01:51Lampbrush Chromosomes