AEC Syndrome

At a glance

AEC is an acronym that stands for Ankyloblepharon-Ectodermal defects and Cleft lip/palate. In addition to these findings, hair anomalies, onychodystrophy, hypohidrosis, and dental anomalies may be present.

Synonym

Hay-Wells Syndrome.

Incidence

This is a very rare form of ectodermal dysplasia with probably fewer than 30 cases described in the medical literature. Females and males are equally affected. There is a wide intra- and interfamilial variability in the phenotype of this disease.

Genetic inheritance

AEC syndrome is inherited as an autosomal dominant trait. The defect is caused by mutations in the Tumor Protein 63 (TP63) gene that has been mapped to chromosome 3q28. Protein TP63 is an important regulator in the processes related to epidermal differentiation and possibly in the development of facial, limb, and urinary tissues.

Diagnosis

Usually based on the typical clinical features and family history.

Clinical aspects

While some patients with developmental delay have been described, the majority is of normal intelligence with some psychosocial issues described as “no different from other patients with chronic diseases.” Short stature, failure to thrive (not well explained and many patients requiring gastric tube feeding), scalp and skin erosions, ankyloblepharon with partial or complete fusion of the eyelids due to tissue bands (ankyloblepharon filiforme adnatum), blepharitis, absent puncta lacrimalia and absent or sparse eyelashes and eyebrows, cup-shaped ears and ear canal stenosis or atresia (with varying degrees of conductive hearing loss), broad nasal bridge and hypoplastic alae nasi, cleft lip and/or palate, maxillary hypoplasia, micrognathia, dental abnormalities (eg, hypodontia, enamel defects, and abnormally shaped teeth), recurrent otitis media, dystrophic or missing nails, and hypohidrosis with reduced heat tolerance are present in the vast majority of these patients. The characteristic scalp erosions lead to scarring alopecia with peri- and intrafollicular neutrophilic infiltrates, focal destruction of follicles with lymphoplasmacytic infiltrates, and diminished density of terminal hair. All patients showed irregularities in the hair shaft structures (eg, twisted, grooved, or flattened hair shafts) and many also in hair pigmentation (eg, pili annulati). This erosive scalp dermatitis can be extensive, result in partial or total alopecia, and is a major source of morbidity secondary to recurrent infections and pain. Similar lesions can be found on the palms, soles, and in the ear canals. Typically, the skin erosions present in the neonatal period, but they can also develop later during the first year of life. Histopathologic examination of skin biopsies from unaffected skin areas reveal epidermal atrophy, hyperkeratosis, focal orthokeratosis, papillomatosis, and superficial perivascular lymphocytic dermatitis with all these changes considered to be mild. Basilar pigmentation and/or pigment incontinence is variable. Scattered melanophages in the superficial and deep dermis (pigment incontinence) most likely reflect postinflammatory changes. Sweat glands and hair follicles are ...