MECP2-related severe neonatal encephalopathy
What is MECP2-related severe neonatal encephalopathy?
MECP2-related severe neonatal encephalopathy is a neurological disorder that primarily affects males and causes brain dysfunction (encephalopathy). Affected males have a small head size (microcephaly), poor muscle tone (hypotonia) in infancy, movement disorders, rigidity, and seizures. Infants with this condition appear normal at birth but then develop severe encephalopathy within the first week of life. These babies experience poor feeding, leading to a failure to gain weight and grow at the expected rate (failure to thrive). Individuals with MECP2-related severe neonatal encephalopathy have severe to profound intellectual disability. Affected males have breathing problems, with some having episodes in which breathing slows or stops for short periods (apnea). As the child ages, the apnea episodes tend to last longer, especially during sleep, and affected babies often require use of a machine to help regulate their breathing (mechanical ventilation). Most males with MECP2-related severe neonatal encephalopathy do not live past the age of 2 because of respiratory failure.
MECP2-related severe neonatal encephalopathy is the most severe condition in a spectrum of disorders with the same genetic cause. The mildest is PPM-X syndrome, followed by MECP2duplication syndrome, then Rett syndrome (which exclusively affects females), and finally MECP2-related severe neonatal encephalopathy.
How common is MECP2-related severe neonatal encephalopathy?
MECP2-related severe neonatal encephalopathy is likely a rare condition. Twenty to 30 affected males have been reported in the scientific literature.
What genes are related to MECP2-related severe neonatal encephalopathy?
Mutations in the MECP2 gene cause MECP2-related severe neonatal encephalopathy. The MECP2gene provides instructions for making a protein called MeCP2 that is critical for normal brain function. Researchers believe that this protein has several functions, including regulating other genes in the brain by switching them on or off as they are needed. The MeCP2 protein likely plays a role in maintaining the normal function of nerve cells, which ensures that connections (synapses) between these cells form properly. The MeCP2 protein may also control the production of different versions of certain proteins in nerve cells. Although mutations in the MECP2 gene disrupt the normal function of nerve cells, it is unclear how these mutations lead to the signs and symptoms of MECP2-related severe neonatal encephalopathy.
Read more about the MECP2 gene.
How do people inherit MECP2-related severe neonatal encephalopathy?
MECP2-related severe neonatal encephalopathy has an X-linked pattern of inheritance. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes in each cell. In males, who have only one X chromosome, a mutation in the only copy of the gene in each cell is sufficient to cause the condition. In females, who have two X chromosomes, a mutation in one of the two copies of the gene in each cell is usually sufficient to cause the condition. However, females with a mutation in the MECP2 gene do not develop MECP2-related severe neonatal encephalopathy. Instead, they typically develop Rett syndrome, which has signs and symptoms that include intellectual disability, seizures, and movement problems.
In some cases, males with MECP2-related severe neonatal encephalopathy inherit the mutation from a mother with mild neurological problems or from a mother with no features related to the mutation. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family.
Where can I find information about diagnosis or management of MECP2-related severe neonatal encephalopathy?
These resources address the diagnosis or management of MECP2-related severe neonatal encephalopathy and may include treatment providers.
- Cincinnati Children's Hospital: MECP2-Related
- Gene Review: MECP2-Related
- Genetic Testing Registry: Severe neonatal-onset encephalopathy with
- Johns Hopkins Children's Center: Failure to
You might also find information on the diagnosis or management of MECP2-related severe neonatal encephalopathy in Educational resources and Patient support.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about MECP2-related severe neonatal encephalopathy?
You may find the following resources about MECP2-related severe neonatal encephalopathy helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for MECP2-related severe neonatal encephalopathy?
- methyl-cytosine phosphate guanine binding protein 2 related severe neonatal encephalopathy
- severe congenital encephalopathy due to MECP2 mutation
- severe neonatal encephalopathy due to MECP2 mutations
What if I still have specific questions about MECP2-related severe neonatal encephalopathy?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
- What does it mean if a disorder seems to run in my family?
- What are the different ways in which a genetic condition can be inherited?
- If a genetic disorder runs in my family, what are the chances that my children will have the condition?
- Why are some genetic conditions more common in particular ethnic groups?
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding MECP2-related severe neonatal encephalopathy?
apnea ; cell ; chromosome ; congenital ; cytosine ; disability ; duplication ; encephalopathy ;failure to thrive ; gene ; guanine ; hypotonia ; inherit ; inheritance ; methyl ; microcephaly ;muscle tone ; mutation ; neonatal ; neurological ; pattern of inheritance ; phosphate ; protein ;respiratory ; sex chromosomes ; spectrum ; syndrome
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (6 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook