Genetic disease
What are the four types of genetic disorders (inherited)?
There are a number of different types of genetic disorders (inherited) and include:
- Single gene inheritance
- Multifactorial inheritance
- Chromosome abnormalities
- Mitochondrial inheritance
6 Symptoms and Signs of Down Syndrome
The baby with Down syndrome has a hallmark appearance. However, every aspect of the appearance does not need to be present as the phenotype, the way the genes make the child look, can be markedly different for each patient. Common Down syndrome symptoms are:
- a small head and short neck,
- flat face, and
- upward slanting eyes, ears are flat and positioned lower than "normal,"
- the tongue protrudes and seems to be too large for the mouth,
- hands tend to be wide,
- short fingers and there is just a single flexion crease in the palm, and
- joints tend to be more flexible and muscles may lack tone.
7 single gene inheritance disorders
Single gene inheritance is also called Mendelian or monogenetic inheritance. Changes or mutations that occur in the DNA sequence of a single gene cause this type of inheritance. There are thousands of known single-gene disorders. These disorders are known as monogenetic disorders (disorders of a single gene).
Single-gene disorders have different patterns of genetic inheritance, including
- autosomal dominant inheritance, in which only one copy of a defective gene (from either parent) is necessary to cause the condition;
- autosomal recessive inheritance, in which two copies of a defective gene (one from each parent) are necessary to cause the condition; and
- X-linked inheritance, in which the defective gene is present on the female, or X-chromosome. X-linked inheritance may be dominant or recessive.
Some examples of single-gene disorders include
- cystic fibrosis,
- alpha- and beta-thalassemias,
- sickle cell anemia (sickle cell disease),
- Marfan syndrome,
- fragile X syndrome,
- Huntington's disease, and
- hemochromatosis.
7 common multifactorial genetic inheritance disorders
Multifactorial inheritance is also called complex or polygenic inheritance. Multifactorial inheritance disorders are caused by a combination of environmental factors and mutations in multiple genes. For example, different genes that influence breast cancer susceptibility have been found on chromosomes 6, 11, 13, 14, 15, 17, and 22. Some common chronic diseases are multifactorial disorders.
Examples of multifactorial inheritance include
- heart disease,
- high blood pressure,
- Alzheimer's disease,
- arthritis,
- diabetes,
- cancer, and
- obesity.
Multifactorial inheritance also is associated with heritable traits such as fingerprint patterns, height, eye color, and skin color.
Comments
Post a Comment