Prelims: Science and Tech (Diseases), Edwards Syndrome
Mains: General Studies-III Science and Technology- Developments and their Applications and Effects in Everyday Life.
Why in the News ?
Researchers have reported chromosomal disorders discovered from prehistoric skeletal remains, dating up to approximately 5,500 years old — including six cases of Down syndrome and one case of Edwards syndrome.
Source: TH
📌 FYI on Prelims
Down’s syndrome
- Down syndrome is a genetic disorder, caused by the presence of an extra chromosome 21 also known as trisomy of chromosome 21.
- It is one of the leading causes of genetic disorders around the world.
- Types of Down syndrome: There are three types of Down syndrome.
- Trisomy 21: About 95% of people with Down syndrome have Trisomy 21. With this type of Down syndrome, each cell in the body has 3 separate copies of chromosome 21 instead of the usual 2 copies.
- Translocation Down syndrome: This type accounts for a small percentage of people with Down syndrome (about 3%). This occurs when an extra part or a whole extra chromosome 21 is present, but it is attached or “trans-located” to a different chromosome rather than being a separate chromosome 21.
- Mosaic Down syndrome: Mosaic means mixture or combination. For children with mosaic Down syndrome, some of their cells have 3 copies of chromosome 21, but other cells have the typical two copies of chromosome 21.
- The primary symptoms of Down’s Syndrome are as follows:
- Mental retardation
- Cognitive impairment may be mild to moderate
- Tilted eyes or Fold of the skin above the eye etc.
- Treatment: Down syndrome is a lifelong condition and it cannot be cured. Early therapy programs can help improve skills.
About:
Edwards syndrome
- It is also known as trisomy 18.
- It is an autosomal chromosomal disorder due to an extra copy of chromosome 18.
- It is a very severe genetic condition that affects child’s body development and growth.
- Symptoms: Children diagnosed with trisomy 18 have a low birth weight, multiple birth defects and defining physical characteristics.
- There are three types of Edwards syndrome
- Complete trisomy 18:
- It is the most common form (94%).
- In this type, every cell contains three complete copies of chromosome 18.
- The extra chromosome is most often of maternal origin.
- Mosaic trisomy 18:
- It is the second most common type (less than 5%).
- In this type, both a complete trisomy 18 and a normal cell line exist.
- Partial trisomy 18:
- In this type, only a partial segment of chromosome 18 is present in triplicate.
- The partial triplicate often results from a balanced translocation or inversion carried by one of the parents.
- Treatment: There are no specific treatments for trisomy 18. Treatment will focus on the symptoms of the condition, such as heart conditions, breathing difficulties and infections.
