Wnt family member 4
The WNT4 gene belongs to a family of WNT genes that play critical roles in development before birth. WNT genes provide instructions for making proteins that participate in chemical signaling pathways in the body. These pathways control the activity of certain genes and regulate the interactions between cells during embryonic development.
The WNT4 gene provides instructions for producing a protein that is important for the formation of the female reproductive system, the kidneys, and several hormone-producing glands. During the development of the female reproductive system, the WNT4 protein regulates the formation of the Müllerian ducts, which are structures in the embryo that develop into the uterus, fallopian tubes, cervix, and the upper part of the vagina. This protein is also involved in development of the ovaries, from before birth through adulthood, and is important for development and maintenance of egg cells (oocytes) in the ovaries. In addition, the WNT4 protein regulates the production of male sex hormones (androgens).
At least three mutations in the WNT4 gene have been found to cause Müllerian aplasia and hyperandrogenism, a condition that affects the reproductive system in females. Girls and women with this condition typically have an underdeveloped or absent uterus and do not menstruate. They may also have abnormally high levels of androgens, which can cause acne and excessive facial hair.
WNT4 gene mutations involved in Müllerian aplasia and hyperandrogenism change single protein building blocks (amino acids) in the WNT4 protein. Researchers suspect that the altered protein cannot be released from cells as it normally would be; the trapped protein is unable to perform its usual functions. Loss of regulation by WNT4 likely disrupts development of the female reproductive system and induces abnormal production of androgens, leading to the features of Müllerian aplasia and hyperandrogenism.
A mutation in the WNT4 gene has been found to cause a severe condition called SERKAL (SEx Reversal and abnormal development of Kidneys, Adrenals, and Lungs) syndrome. In this condition, male sex development may occur despite the chromosome pattern typical of females. SERKAL syndrome has been reported in only one family and likely is not compatible with life. The mutation that causes SERKAL syndrome replaces the protein building block (amino acid) alanine with the amino acid valine at position 114 in the WNT4 protein (written as Ala114Val or A114V). This mutation is present in both copies of the WNT4 gene in each cell and likely eliminates the function of the WNT4 protein. The absence of WNT4 protein results in the wide variety of developmental abnormalities seen in SERKAL syndrome.
A duplication of genetic material in a specific region of chromosome 1 can result in an extra copy of the WNT4 gene. Having an additional copy of this gene leads to the production of extra WNT4 protein. People with this duplication may develop some female features despite having the chromosome pattern typical of males. These individuals can have an underdeveloped uterus and nonfunctional testes.
- wingless-type MMTV integration site family member 4
- wingless-type MMTV integration site family, member 4
- WNT-4 protein