Johnson Neuroectodermal Syndrome

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.