EEM syndrome denotes a disorder characterized by ectodermal dysplasia, ectrodactyly, and macular dystrophy. The ectodermal dysplasia consists of hypotrichosis affecting scalp hair, eyebrows, and eyelashes, with partial anodontia. Different degrees of absence deformities as well as syndactyly have been described, the hands often being more severely affected than the feet. The retinal lesion appears as a central geographic atrophy of the retinal pigment epithelium and choriocapillary layer of the macular area with coarse hyperpigmentations and sparing of the larger choroidal vessels (summary by Kjaer et al., 2005).

Ectodermal dysplasia-syndactyly syndrome (EDSS) is characterized by sparse to absent scalp hair, eyebrows, and eyelashes, hypoplastic nails, tooth enamel hypoplasia, conical-shaped teeth, palmoplantar keratoderma, and partial cutaneous syndactyly (summary by Raza et al., 2015). Genetic Heterogeneity of Ectodermal Dysplasia-Syndactyly Syndrome Ectodermal dysplasia-syndactyly syndrome-2 (EDSS2; 613576) maps to chromosome 7p21-p14.

Any Meier-Gorlin syndrome in which the cause of the disease is a mutation in the CDC45 gene.

Sweeney-Cox syndrome (SWCOS) is characterized by striking facial dysostosis, including hypertelorism, deficiencies of the eyelids and facial bones, cleft palate/velopharyngeal insufficiency, and low-set cupped ears (Kim et al., 2017).

Townes-Brocks syndrome (TBS) is characterized by the triad of imperforate anus (84%), dysplastic ears (87%; overfolded superior helices and preauricular tags; frequently associated with sensorineural and/or conductive hearing impairment [65%]), and thumb malformations (89%; triphalangeal thumbs, duplication of the thumb [preaxial polydactyly], and rarely hypoplasia of the thumbs). Renal impairment (42%), including end-stage renal disease (ESRD), may occur with or without structural abnormalities (mild malrotation, ectopia, horseshoe kidney, renal hypoplasia, polycystic kidneys, vesicoutereral reflux). Congenital heart disease occurs in 25%. Foot malformations (52%; flat feet, overlapping toes) and genitourinary malformations (36%) are common. Intellectual disability occurs in approximately 10% of individuals. Rare features include iris coloboma, Duane anomaly, Arnold-Chiari malformation type 1, and growth retardation.