What causes severe mental retardation?

What causes severe mental retardation?

Illness or injury. Infections like meningitis, whooping cough, or the measles can lead to intellectual disability. Severe head injury, near-drowning, extreme malnutrition, infections in the brain, exposure to toxic substances such as lead, and severe neglect or abuse can also cause it.

What is the most severe genetic disorder?

The 7 Most Common Genetic Disorders

1. Down Syndrome. When the 21st chromosome is copied an extra time in all or some cells, the result is down syndrome – also known as trisomy 21.
2. Cystic Fibrosis.
3. Thalassemia.
4. Sickle Cell Anemia.
5. Huntington’s Disease.
6. Duchenne’s Muscular Dystrophy.
7. Tay-Sachs Disease.

What are the 5 most common genetic disorders?

What You Need to Know About 5 Most Common Genetic Disorders

• Down Syndrome.
• Thalassemia.
• Cystic Fibrosis.
• Tay-Sachs disease.
• Sickle Cell Anemia.
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How many human genetic disorders are known?

There are well over 6,000 known genetic disorders, and new genetic disorders are constantly being described in medical literature. More than 600 of these disorders are treatable. Around 1 in 50 people are affected by a known single-gene disorder, while around 1 in 263 are affected by a chromosomal disorder.

How do genetic disorders occur?

Genetic disorders can be caused by a mutation in one gene (monogenic disorder), by mutations in multiple genes (multifactorial inheritance disorder), by a combination of gene mutations and environmental factors, or by damage to chromosomes (changes in the number or structure of entire chromosomes, the structures that …

What are 3 genetic disorders?

There are three types of genetic disorders:

• Single-gene disorders, where a mutation affects one gene. Sickle cell anemia is an example.
• Chromosomal disorders, where chromosomes (or parts of chromosomes) are missing or changed.
• Complex disorders, where there are mutations in two or more genes.

How are genetic disorders diagnosed?

Most of the time, genetic disorders are diagnosed through a specific test, which can include examining chromosomes or DNA (the tiny proteins that make up genes), or testing the blood for certain enzymes that may be abnormal. Studying enzymes is called biochemical genetic testing.

What genetic testing can reveal?

Overview. Genetic testing involves examining your DNA, the chemical database that carries instructions for your body’s functions. Genetic testing can reveal changes (mutations) in your genes that may cause illness or disease.

What are the three types of genetic testing?

The following information describes the three main types of genetic testing: chromosome studies, DNA studies, and biochemical genetic studies. Tests for cancer susceptibility genes are usually done by DNA studies.

How much does it cost to get a genetic test?

The cost of genetic testing can range from under $100 to more than $2,000, depending on the nature and complexity of the test. The cost increases if more than one test is necessary or if multiple family members must be tested to obtain a meaningful result.