Virtually all individuals with Woodhouse-Sakati syndrome (WSS) have the endocrine findings of hypogonadism (evident at puberty) and progressive childhood-onset hair thinning that often progresses to alopecia totalis in adulthood. More than half of individuals have the neurologic findings of progressive extrapyramidal movements (dystonic spasms with dystonic posturing with dysarthria and dysphagia), moderate bilateral postlingual sensorineural hearing loss, and mild intellectual disability. To date, more than 40 families (including 33 with a molecularly confirmed diagnosis) with a total of 88 affected individuals have been reported in the literature.

Cranioectodermal dysplasia (CED) is a ciliopathy with skeletal involvement (narrow thorax, shortened proximal limbs, syndactyly, polydactyly, brachydactyly), ectodermal features (widely spaced hypoplastic teeth, hypodontia, sparse hair, skin laxity, abnormal nails), joint laxity, growth deficiency, and characteristic facial features (frontal bossing, low-set simple ears, high forehead, telecanthus, epicanthal folds, full cheeks, everted lower lip). Most affected children develop nephronophthisis that often leads to end-stage kidney disease in infancy or childhood, a major cause of morbidity and mortality. Hepatic fibrosis and retinal dystrophy are also observed. Dolichocephaly, often secondary to sagittal craniosynostosis, is a primary manifestation that distinguishes CED from most other ciliopathies. Brain malformations and developmental delay may also occur.

A congenital defect characterized by the absence of one or more permanent teeth, including oligodontia, hypodontia, and adontia of the of permanent teeth.

Van der Woude syndrome (VWS) is a dominantly inherited developmental disorder characterized by pits and/or sinuses of the lower lip, and cleft lip and/or cleft palate (CL/P, CP). It is the most common cleft syndrome. For a discussion of genetic heterogeneity of van der Woude syndrome, see VWS1 (119300).

Any tooth agenesis in which the cause of the disease is a mutation in the EDA gene.

Zlotogora-Ogur syndrome is an ectodermal dysplasia syndrome with characteristics of hair, skin and teeth anomalies, facial dysmorphism with cleft lip and palate, cutaneous syndactyly and, in some cases, intellectual disability.The prevalence is unknown but to date, less than 50 cases have been described in the literature. Caused by mutations in the gene PVRL1 (11q23-q24) which encodes nectin-1, the principal receptor used by alpha-herpesviruses to mediate entry into human cells. Transmission is autosomal recessive.

Hypohidrotic ectodermal dysplasia (HED) is characterized by hypotrichosis (sparseness of scalp and body hair), hypohidrosis (reduced ability to sweat), and hypodontia (congenital absence of teeth). The cardinal features of classic HED become obvious during childhood. The scalp hair is thin, lightly pigmented, and slow growing. Sweating, although present, is greatly deficient, leading to episodes of hyperthermia until the affected individual or family acquires experience with environmental modifications to control temperature. Only a few abnormally formed teeth erupt, at a later-than-average age. Physical growth and psychomotor development are otherwise within normal limits. Mild HED is characterized by mild manifestations of any or all the characteristic features.

Hypohidrotic ectodermal dysplasia (HED) is characterized by hypotrichosis (sparseness of scalp and body hair), hypohidrosis (reduced ability to sweat), and hypodontia (congenital absence of teeth). The cardinal features of classic HED become obvious during childhood. The scalp hair is thin, lightly pigmented, and slow growing. Sweating, although present, is greatly deficient, leading to episodes of hyperthermia until the affected individual or family acquires experience with environmental modifications to control temperature. Only a few abnormally formed teeth erupt, at a later-than-average age. Physical growth and psychomotor development are otherwise within normal limits. Mild HED is characterized by mild manifestations of any or all the characteristic features.