The official name of this gene is "cyclin-dependent kinase-like 5."

CDKL5 is the gene's official symbol. The CDKL5 gene is also known by other names, listed below.

The CDKL5 gene provides instructions for making a protein that is essential for normal brain development. Although little is known about the protein's function, it may play a role in regulating the activity of other genes. The CDKL5 protein acts as a kinase, which is an enzyme that changes the activity of other proteins by adding a cluster of oxygen and phosphate atoms (a phosphate group) at specific positions. Researchers have not determined which proteins are targeted by the CDKL5 protein.

At least 10 mutations in the CDKL5 gene have been identified in girls with an atypical form of Rett syndrome known as the early-onset seizure variant. This severe form of the disorder includes many of the features of classic Rett syndrome (including developmental problems, loss of language skills, and repeated hand wringing or hand washing movements), but also causes recurrent seizures beginning in infancy. Some CDKL5 mutations change a single protein building block (amino acid) in a region of the CDKL5 protein that is critical for its kinase function. Other mutations lead to the production of an abnormally short, nonfunctional version of the protein. Researchers are working to determine how these changes result in seizures and the characteristic features of Rett syndrome in affected children.other disorders - caused by mutations in the CDKL5 gene

Mutations in the CDKL5 gene also cause a disorder called X-linked infantile spasm syndrome (ISSX) or West syndrome. Like the early-onset seizure variant of Rett syndrome, X-linked infantile spasm syndrome is characterized by recurrent seizures that begin in infancy. Children with this condition also have severe to profound intellectual disability and may have other brain abnormalities. The CDKL5 mutations responsible for X-linked infantile spasm syndrome lead to the production of an abnormally short, nonfunctional version of the CDKL5 protein. It remains uncertain how these defects cause seizures and intellectual disability.

Cytogenetic Location: Xp22

Molecular Location on the X chromosome: base pairs 18,443,724 to 18,671,748

The CDKL5 gene is located on the short (p) arm of the X chromosome at position 22.

More precisely, the CDKL5 gene is located from base pair 18,443,724 to base pair 18,671,748 on the X chromosome.

See How do geneticists indicate the location of a gene? in the Handbook.

You and your healthcare professional may find the following resources about CDKL5 helpful.

• Gene Tests - DNA tests ordered by healthcare professionals (2 links)

You may also be interested in these resources, which are designed for genetics professionals and researchers.

• PubMed - Recent literature

• OMIM - Genetic disorder catalog (2 links)

• Research Resources - Tools for researchers (4 links)

• CDKL5_HUMAN
• serine/threonine kinase 9
• STK9

See How are genetic conditions and genes named? in the Handbook.

The Handbook provides basic information about genetics in clear language.

• What is DNA?
• What is a gene?
• How do genes direct the production of proteins?
• How can gene mutations affect health and development?

These links provide additional genetics resources that may be useful.

• Genetics education
• Human Genome Project
• Resources for Genetic Researchers

acids ; amino acid ; atom ; atypical ; enzyme ; gene ; kinase ; mutation ; oxygen ; phosphate ; protein ; seizure ; serine ; syndrome ; threonine ; threonine kinase

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

See also Understanding Medical Terminology.

References (7 links)