Globozoospermia (Globozoospermia) - Gen DPY19L2.
The globozoospermia is a disease that affects only males, characterized by a morphological alteration that generates sperm and infertility. The sperm of men with globozoospermia have a round head without acrosome. Abnormal sperm is unable to fertilize an egg, so that infertility occurs.
Most often, the globozoospermia is due to mutations in the gene DPY19L2. Mutations in this gene are found in about 70% of affected males. Mutations in other genes probably cause globozoospermia.
The DPY19L2 gene, located on the long arm of chromosome 12 (12q14.2), encodes a protein found in developing sperm cells. This protein plays a role in the development of the acrosome. The acrosome contains enzymes that break down the outer membrane of the egg cells, allowing sperm to fertilize an egg. Acrosome developing is attached to the cell nucleus. The DPY19L2 protein, found within the membrane of the nucleus, helps bind the acrosome being formed to the nuclear membrane. As the acrosome sperm develops and matures, the acrosome is moved to the end of the sperm head, which helps extend oval head takes shape.
They have identified at least 17 genetic mutations in DPY19L2 in men with globozoospermia. Most of these genetic changes remove large regions of the gene or the entire gene. Other mutations change the amino acids in protein DPY19L2, prococando a loss of functional DPY19L2 protein. Without this protein, acrosome developing is not attached to the core and is removed from the cell. As a result, no sperm acrosome and sperm head lengthens no. Abnormal sperm can not get through the outer membrane of an egg to fertilize it , causing infertility in males affected.
This disease is inherited in an autosomal recessive pattern, that is, both copies of the gene in every cell must have mutations for alteration is expressed. The parents of an individual with an autosomal recessive disease have a copy of the mutated gene, but usually show no signs and symptoms of the disease.
Tests in IVAMI: in IVAMI perform detection of mutations associated with globozoospermia, by complete PCR amplification of exons DPY19L2 gene, and subsequent sequencing.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).