Atypical Rett syndrome
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
Age of Onset
Autosomal dominant ?A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease
Autosomal recessive ?Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype
X-linked dominant ?X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.
X-linked recessive ?Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder
Mitochondrial or multigenic ?Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.
Multigenic or multifactor ?Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.
Other Names (AKA)
Rett like syndrome; Rett syndrome variant
Congenital and Genetic Diseases; Nervous System Diseases
- The early-onset seizure type is characterized by
seizuresin the first months of life with later development of Rett features (including developmental problems, loss of language skills, and repeated hand wringing or hand washing movements). It is frequently caused by mutationsin the X-linkedCDKL5 gene(Xp22).
- The congenital variant is the most severe form of atypical Rett syndrome, with onset of classic Rett features during the first three months of life. This variant is generally caused by mutations in the FOXG1 gene (14q11-q13).
- The forme fruste is a milder variant with onset in early childhood and an incomplete and prolonged course.
- The late childhood regression form is characterized by a normal head circumference and by a more gradual and later onset (late childhood) regression of language and motor skills.
- The preserved speech variant is marked by recovery of some verbal and manual skills and is caused in at least some cases by mutations in the MECP2 (Xq28) gene, which is also responsible for the majority of cases of classic Rett syndrome.
This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.
|Medical Terms||Other Names||
|80%-99% of people have these symptoms|
Loss of developmental milestones
Mental deterioration in childhood
[ more ]
[ more ]
|Functional motor deficit||0004302|
|Loss of speech||0002371|
|Poor eye contact||0000817|
[ more ]
|Stereotypical hand wringing||0012171|
|30%-79% of people have these symptoms|
|Functional abnormality of the gastrointestinal tract||0012719|
Inability to coordinate movements when walking
|Loss of ability to walk||0006957|
Inability to speak
[ more ]
[ more ]
Disproportionately small hands
Involuntary muscle stiffness, contraction, or spasm
|Sudden episodic apnea||0002882|
|5%-29% of people have these symptoms|
|Delayed gross motor development||
Delayed motor skills
[ more ]
|Impaired pain sensation||
Decreased pain sensation
Mental retardation, borderline-mild
Mild and nonprogressive mental retardation
Mild mental retardation
[ more ]
[ more ]
Low muscle tone, in neonatal onset
Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.
Conditions with similar signs and symptoms from Orphanet
Differential diagnoses include Angelman syndrome, autism, cerebral palsy, inborn errors of metabolism and severe intellectual deficit (see these terms).
Visit the Orphanet disease page for more information.
Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
International Foundation for CDKL5 Research (IFCR)
P.O. Box 926
Wadsworth, OH 44282
These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.
- Genetics Home Reference (GHR) contains information on Atypical Rett syndrome. This website is maintained by the National Library of Medicine.
- The National Institute of Neurological Disorders and Stroke (NINDS) collects and disseminates research information related to neurological disorders. Click on the link to view information on this topic.
- The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
- Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
- The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
- Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.