With the advance of science, Walther Flemming discovered in 1882 that our genetic material is carried by a thread-like structure found in our cells called chromosomes. Ever since, scientists were able to discover several diseases related to chromosomal abnormalities. In this article, we will understand how chromosomal abnormalities occur and the different types of chromosomal abnormalities.
1.How do chromosomal abnormalities happen?
A normal person has a set of 23 pairs of chromosomes in each cell. One of the chromosomal pairs is called the sex chromosomes which determines our gender: women have XX chromosomes while men have XY chromosomes. During pregnancy, cells go through division and replication to progressively form the baby. Cell division and replication is normal when each cell has 23 pairs of chromosomes. Sometimes, an error occurs for unknown reason during cell division and replication resulting into cells which chromosomes are not all divided into pairs. Such errors could be chromosomal trisomy if three chromosomes are grouped together or monosomy if a chromosome is not paired with another one. Some recent researches discovered that some medications or exposure to high intensity radiation can cause chromosomal abnormalities.
2.Which diseases are caused by chromosomal trisomy?
If the trisomy is in chromosome 21, then the baby will be having Down’s syndrome. This also means that instead of having 46 chromosomes in one cell, a Down baby has 47 chromosomes in one cell. Down syndrome people have some common physical characteristics: flat and round face, short neck, small ears, small hands/feets, and sometimes they are shorter than others.
In case the trisomy is in chromosome 18, then the baby will be having Edward’s disease which is more rare but more serious compared to Down’s syndrome. Many babies with Edward’s disease die shortly after birth as it severely affects the heart. Babies with Edward’s disease usually have a cleft palate (when the mouth roof is not fully closed), some defects in the lung/kidney/intestine, deformed feet/hands and a small head/jaw.
Patau’s disease happens if the baby has trisomy in chromosome 13. Babies with Patau usually have an extra finger/toe, a cleft palate, small head and eyes closer than normal. Not all babies with Patau survive until teenagehood as the brain development might be severely affected.
3.Can we treat diseases related to chromosomal trisomy?
Even if we cannot treat chromosomal trisomy, pregnant women can now detect chromosomal abnormalities during pregnancy thanks to chromosomal karyotyping. Nevertheless, researchers and doctors try to help people with chromosomal diseases to overcome their limitations.
Having a child with chromosomal abnormality requires from us parents’ patience, wisdom, but most importantly a lot of love.