A chromosomal issue, abnormality, variation, or transformation is a missing, extra, or unpredictable bit of chromosomal DNA. It tends to be from a regular number of chromosomes or a basic anomaly in at least one chromosomes. Some chromosomal anomalies happen when there is an additional chromosome, while others happen when a segment of a chromosome is erased or copied. Instances of chromosomal variations from the norm incorporate Down disorder, Trisomy 18, Trisomy 13, Klinefelter condition, XYY condition, Turner disorder and triple X disorder. The most widely recognized sort of chromosomal irregularity is known as aneuploidy, a strange chromosome number because of an extra or missing chromosome. A great many people with aneuploidy have trisomy rather than monosomy. Chromosomal Variations from the norm in Pregnancy. By a chromosomal anomaly happens when a hatchling has either the wrong number of chromosomes, off base measure of DNA inside a chromosome or chromosomes that are fundamentally defective