Disease Profile

Johnson neuroectodermal syndrome

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.
<1 / 1 000 000

< 331

US Estimated

< 514

Europe Estimated

Age of Onset

Childhood

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ICD-10

Q87.8

Inheritance

Autosomal dominant ?A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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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

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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.

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X-linked recessive ?Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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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.

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Not applicable

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Other Names (AKA)

Johnson-Mcmillin syndrome; Alopecia anosmia deafness hypogonadism syndrome; AADH syndrome

Categories

Congenital and Genetic Diseases; Nervous System Diseases; Skin Diseases

Summary

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
orphanet

Orpha Number: 2316

Definition
Johnson neuroectodermal syndrome is characterised by alopecia, anosmia or hyposmia, conductive deafness with malformed ears and microtia and/or atresia of the external auditory canal, and hypogonadotropic hypogonadism.

Epidemiology
So far, less than 30 cases have been described in the literature.

Clinical description
Other variable features include a congenital heart defect, facial asymmetry, intellectual deficit, cleft palate, choanal stenosis and an increased tendency for dental caries.

Etiology
The aetiology is unknown but the combination of developmental anomalies present in patients with this syndrome is suggestive of an embryological defect in the formation of the neuroectodermal derivatives of cephalic neural crest.

Genetic counseling
The syndrome is transmitted as an autosomal dominant trait.

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
Alopecia
Hair loss
0001596
Atresia of the external auditory canal
Absent ear canal
0000413
Conductive hearing impairment
Conductive deafness
Conductive hearing loss

[ more ]

0000405
Hypogonadism
Decreased activity of gonads
0000135
Sparse hair
0008070
30%-79% of people have these symptoms
Absent eyebrow
Failure of development of eyebrows
0002223
Absent eyelashes
Failure of development of eyelashes
0000561
Carious teeth
Dental cavities
Tooth cavities
Tooth decay

[ more ]

0000670
Facial asymmetry
Asymmetry of face
Crooked face
Unsymmetrical face

[ more ]

0000324
Facial palsy
Bell's palsy
0010628
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation

[ more ]

0001249
Microtia
Small ears
Underdeveloped ears

[ more ]

0008551
Protruding ear
Prominent ear
Prominent ears

[ more ]

0000411
Severe short stature
Dwarfism
Proportionate dwarfism
Short stature, severe

[ more ]

0003510
5%-29% of people have these symptoms
Anosmia
Lost smell
0000458
Bulbous nose
0000414
Choanal atresia
Blockage of the rear opening of the nasal cavity
Obstruction of the rear opening of the nasal cavity

[ more ]

0000453
Choanal stenosis
Narrowing of the rear opening of the nasal cavity
0000452
Cleft palate
Cleft roof of mouth
0000175
Decreased testicular size
Small testes
Small testis

[ more ]

0008734
Downslanted palpebral fissures
Downward slanting of the opening between the eyelids
0000494
Everted lower lip vermilion
Drooping lower lip
Outward turned lower lip

[ more ]

0000232
Failure to thrive
Faltering weight
Weight faltering

[ more ]

0001508
Hypohidrosis
Decreased ability to sweat
Decreased sweating
Sweating, decreased

[ more ]

0000966
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Small head circumference
Reduced head circumference

[ more ]

0000252
Micropenis
Short penis
Small penis

[ more ]

0000054
Multiple cafe-au-lait spots
0007565
Patent ductus arteriosus
0001643
Preaxial hand polydactyly
Extra thumb
0001177
Retrognathia
Receding chin
Receding lower jaw
Weak chin
Weak jaw

[ more ]

0000278
Right aortic arch
0012020
Tetralogy of Fallot
0001636
Ventricular septal defect
Hole in heart wall separating two lower heart chambers
0001629
Percent of people who have these symptoms is not available through HPO
Abnormality of cardiovascular system morphology
0030680
Autosomal dominant inheritance
0000006
Growth delay
Delayed growth
Growth deficiency
Growth failure
Growth retardation
Poor growth
Retarded growth

[ more ]

0001510
Hypogonadotropic hypogonadism
0000044
Short stature
Decreased body height
Small stature

[ more ]

0004322

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

    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.

    In-Depth Information

    • 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 Johnson neuroectodermal syndrome. Click on the link to view a sample search on this topic.