Mosaic (genetics)

Mosaic (genetics)

Mosaic (genetics) refers to the presence of two or more populations of cells with different genotypes in one individual, who has developed from a single fertilized egg. Mosaicism has been reported in many different tissues but is particularly prevalent in the skin, blood, and nervous system.

Causes

Mosaicism can result from a mutation during development which is propagated to only a subset of the adult cells. Some common causes include mutations in individual cells, a phenomenon known as somatic mutation, and errors in mitosis.

Types of Mosaicism

There are several types of mosaicism, including:

• Gonadal mosaicism: This occurs when some of the cells in the reproductive cells have a different genetic makeup from the rest of the body. This can result in a child inheriting a genetic condition that neither parent has.

• Somatic mosaicism: This occurs when the mutation happens after fertilization during the early stages of embryonic development. Some cells have the mutation, and some do not.

• Tissue-specific mosaicism: This occurs when the mutation is only in certain types of cells or tissues in the body.

Diagnosis

Diagnosis of mosaicism can be challenging due to the random distribution of affected cells in different tissues. It often involves genetic testing, including DNA sequencing and karyotyping.

Treatment

Treatment for mosaicism depends on the specific genetic changes and their effects on the body. It often involves managing the symptoms and complications of the condition.

See also

• Chimera (genetics)
• Genetic disorder
• Genetic variation