What is Johnson Neuroectodermal Syndrome?
Johnson Neuroectodermal is a rare genetic syndrome that presents with conductive hearing loss, alopecia, and microtia which involves the auditory canal of the ear.
There are, to date, less than 30 cases recorded worldwide making it extremely rare.
This syndrome is also known as:
AADH Syndrome; Alopecia-anosmia-deafness-hypogonadism Syndrome; Johnson-McMillin Syndrome; JMS
What gene change causes Johnson Neuroectodermal syndrome?
As yet no precise gene has yet been identified. It is inherited in an autosomal dominant pattern.
In the case of autosomal dominant inheritance, just one parent is the carrier of the gene mutation, and they have a 50% chance of passing it onto each of their children. Syndromes inherited in an autosomal dominant inheritance are caused by just one copy of the gene mutation.
What are the main symptoms of Johnson Neuroectodermal syndrome?
The main symptoms include alopecia, which is hair loss. Many individuals also have an absent or malformed ear canal. Conductive hearing loss and hypogonadism (reduced activity of the gonads) are also common.
Other symptoms of the syndrome may include missing eyebrows and eyelashes, a susceptibility to dental cavities, facial asymmetry, small ears, prominent ears, and dwarfism.
Possible clinical traits/features:
Short stature, Hypohidrosis, Hypogonadotropic hypogonadism, Cognitive impairment, Abnormal eyelash morphology, Abnormality of the genital system, Abnormality of the sense of smell, Abnormality of the pinna, Choanal stenosis, Choanal atresia, Aplasia/Hypoplasia of the eyebrow, Cafe-au-lait spot, Carious teeth, Alopecia, Absent eyebrow, Anosmia, Multiple cafe-au-lait spots, Intellectual disability, Abnormal nasal morphology, Microtia, Micropenis, Preaxial hand polydactyly, Patent ductus arteriosus, Autosomal dominant inheritance, Retrognathia, Protruding ear, Decreased testicular size, Conductive hearing impairment, Downslanted palpebral fissures, Everted lower lip vermilion, Cleft palate, Atresia of the external auditory canal, Facial palsy, Facial asymmetry, Absent eyelashes, Developmental regression, Sparse hair, Ventricular septal defect, Tetralogy of Fallot, Right aortic arch, Microcephaly.
How is it diagnosed?
To find out if someone has a diagnosis of Johnson Neuroectodermal syndrome, it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.
