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Disease Profile
Severe achondroplasia with developmental delay and acanthosis nigricans
Prevalence
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.
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.
<1 / 1 000 000
Age of onset
Childhood
ICD-10
Q77.4
Inheritance
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.
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.
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.
Not applicable
Other names (AKA)
SADDAN dysplasia; Skeleton skin brain syndrome; Severe achondroplasia with developmental delay and acanthosis nigricans;
Categories
Congenital and Genetic Diseases
Summary
The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
Orpha Number: 85165
Definition
Severe achondroplasiadevelopmental delay acanthosis nigricans syndrome is characterised by the association of severe achondroplasia with developmental delay and acanthosis nigricans. It has been described in four unrelated individuals. Structural central nervous system anomalies, seizures and hearing loss were also reported, together with bowing of the clavicle, femur, tibia and fibula in some cases. The syndrome is caused by a Lys650Met substitution in the kinase domain of fibroblast growth factor receptor 3 (encoded by the FGFR3 gene ; 4p16.3).
Visit the Orphanet disease page for more resources.
Symptoms
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 |
Learn More:
HPO ID
|
|---|---|---|
| 80%-99% of people have these symptoms | ||
|
Darkened and thickened skin
|
0000956 | |
| Aplasia/Hypoplasia of the mandible | 0009118 | |
| Brain atrophy |
Brain degeneration
Brain wasting
[ more ] |
0012444 |
| Enlarged cerebellum | 0012081 | |
| Generalized-onset |
0002197 | |
| Hypoplasia of the |
Underdevelopment of part of brain called corpus callosum
|
0002079 |
|
Early and severe mental retardation
Mental retardation, severe
Severe mental retardation
[ more ] |
0010864 | |
| Metaphyseal chondrodysplasia | 0005871 | |
| Severe global |
0011344 | |
| 30%-79% of people have these symptoms | ||
| Abnormal clavicle morphology |
Abnormal collarbone
|
0000889 |
| Femoral bowing |
Bowed thighbone
|
0002980 |
| Fibular bowing |
Bowed calf bone
|
0010502 |
|
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference
[ more ] |
0000252 | |
| Tibial bowing |
Bowed shankbone
Bowed shinbone
[ more ] |
0002982 |
| 5%-29% of people have these symptoms | ||
| Congestive heart failure |
Cardiac failure
Cardiac failures
Heart failure
[ more ] |
0001635 |
| Exotropia |
Outward facing eye ball
|
0000577 |
| Gastroesophageal reflux |
Acid reflux
Acid reflux disease
Heartburn
[ more ] |
0002020 |
| High myopia |
Severe near sightedness
Severely close sighted
Severely near sighted
[ more ] |
0011003 |
| Pulmonary arterial |
Increased blood pressure in blood vessels of lungs
|
0002092 |
| Percent of people who have these symptoms is not available through HPO | ||
| 0000006 | ||
| Central apnea | 0002871 | |
| Depressed nasal bridge |
Depressed bridge of nose
Flat bridge of nose
Flat nasal bridge
Flat, nasal bridge
Flattened nasal bridge
Low nasal bridge
Low nasal root
[ more ] |
0005280 |
| Frontal bossing | 0002007 | |
| Global developmental delay | 0001263 | |
| Hearing impairment |
Deafness
Hearing defect
[ more ] |
0000365 |
|
Too much cerebrospinal fluid in the brain
|
0000238 | |
| Intellectual disability |
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] |
0001249 |
| Kyphosis |
Hunched back
Round back
[ more ] |
0002808 |
| Lumbar hyperlordosis |
Excessive inward curvature of lower spine
|
0002938 |
| Megalencephaly | 0001355 | |
| Mesomelia |
Disproportionately short middle portion of limb
|
0003027 |
| Midface retrusion |
Decreased size of midface
Midface deficiency
Underdevelopment of midface
[ more ] |
0011800 |
| Otitis media |
Middle ear infection
|
0000388 |
| Platyspondyly |
Flattened vertebrae
|
0000926 |
| Redundant skin |
Loose redundant skin
Redundant skin folds
Sagging, redundant skin
[ more ] |
0001582 |
| Rhizomelia |
Disproportionately short upper portion of limb
|
0008905 |
| Seizure | 0001250 | |
| Severe |
Dwarfism
Proportionate dwarfism
Short stature, severe
[ more ] |
0003510 |
| Sleep apnea |
Pauses in breathing while sleeping
|
0010535 |
| Wide anterior fontanel |
Wider-than-typical soft spot of skull
|
0000260 |
Organizations
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.
Organizations Supporting this Disease
-
Little People of America, Inc.
617 Broadway #518
Sonoma, CA 95476
Toll-free: 1-888-572-2001
Telephone: +1-714-368-3689
Fax: +1-707-721-1896
E-mail: info@lpaonline.org
Website: https://www.lpaonline.org/ -
Little People UK
P.O Box 1292
Peterborough
PE2 2NT
United Kingdom
Telephone: 07925893398
E-mail: info@littlepeopleuk.org
Website: https://littlepeopleuk.org/
Learn more
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.
Where to Start
- Genetics Home Reference (GHR) contains information on Severe achondroplasia with developmental delay and acanthosis nigricans. This website is maintained by the National Library of Medicine.
In-Depth Information
- GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
- 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.
- Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine.
- Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
- PubMed is a searchable database of medical literature and lists journal articles that discuss Severe achondroplasia with developmental delay and acanthosis nigricans. Click on the link to view a sample search on this topic.