BACKGROUND: Ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome, also known as Hay-Wells syndrome, is a rare genetic syndrome with ectodermal dysplasia. About 100 patients have been reported to date. It is associated to a heterozygous mutation of the tumor protein p63 (TP63) gene, located on chromosome 3q28. Typical clinical manifestations include: filiform ankyloblepharon adnatum (congenital adherence of the eyelids), ectodermal abnormalities (sparse and frizzy hair, skin defects, nail alterations, dental changes and hypohidrosis), and cleft lip/palate. Diagnostic suspicion is based on clinical signs and confirmed by genetic testing.
UNASSIGNED: We hereby report on a female newborn with erythroderma, thin lamellar desquamations, extensive skin erosions, sparse and wiry hair, filiform ankyloblepharon adnatum, agenesis of the lachrymal puncta, cleft palate and nail dysplasia. Her phenotype was compatible with AEC syndrome. Then, based on the clinical suspicion, sequencing analysis of the TP63 gene was performed, and revealed a de novo novel missense mutation. Eyelids adherence and cleft palate underwent surgical correction, while skin erosions were treated with topical antibiotics/antifungals and emollient/re-epithelizing creams. A surgical reconstruction is presently planned for the agenesis of the lachrymal puncta. The infant currently is 17 months of age and is included in a multidisciplinary follow-up. At present shows growth impairment and mild developmental delay, and typical signs of ectodermal dysplasia with small areas of dermatitis lesions on the scalp, without further abnormalities.
CONCLUSIONS: Our report underlines the relevance of an early and careful clinical evaluation in neonates with ankyloblefaron, facial dysmorphism, and signs of ectodermal dysplasia. In these cases, the suspicion of AEC syndrome must be promptly raised, and sequencing analysis of TP63 early performed as well. An individualized, multidisciplinary and long-term follow-up should be guaranteed to affected subjects and their families, also to identify associated morbidities and prevent possible serious complications and adverse outcomes.

The p63 gene encodes a master regulator of epidermal commitment, development, and differentiation. Heterozygous mutations in the DNA binding domain cause Ectrodactyly, Ectodermal Dysplasia, characterized by limb deformation, cleft lip/palate, and ectodermal dysplasia while mutations in in the C-terminal domain of the α-isoform cause Ankyloblepharon-Ectodermal defects-Cleft lip/palate (AEC) syndrome, a life-threatening disorder characterized by skin fragility, severe, long-lasting skin erosions, and cleft lip/palate. The molecular disease mechanisms of these syndromes have recently become elucidated and have enhanced our understanding of the role of p63 in epidermal development. Here we review the molecular cause and functional consequences of these p63-mutations for skin development and discuss the consequences of p63 mutations for female fertility.

Ectrodactyly-Ectodermal dysplasia-Cleft lip/palate (EEC) syndrome and Ankyloblepharon-Ectodermal defects-Cleft lip/palate (AEC) syndrome belong to p63 syndromes, a group of rare disorders exhibiting a wide variety of clinical manifestations. TP63 mutations have been reported to be associated with both EEC and AEC.
Analysis of whole exome sequencing (WES) from patients with EEC or AEC syndrome and Sanger sequencing from family members.
We confirmed that three Chinese pedigrees affected with EEC or AEC harboring a distinct TP63 mutation, and described novel clinical phenotypes of EEC and AEC, including the presence of cubitus valgus deformity and taurodontism, which were discordant to their classical disease features. We also analyzed the genotype-phenotype correlation based on our findings.
We reported that the cubitus valgus deformity in patients with EEC and severe taurodontism in a patient with AEC had not been mentioned previously. Our study expands the phenotypic spectrum of EEC and AEC syndrome.

Sweating deficiency has been reported to represent a cardinal symptom of ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome and ankyloblepharon-ectodermal dysplasia-cleft lip/palate syndrome, two rare p63-associated disorders. According to online resources, hypohidrosis may lead to most life-threatening complications in affected patients. Thus, counseling on the prevention of hyperthermia would be indispensable in case of such syndromes, although detailed information on this issue is missing in the literature. We investigated 14 individuals with ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome (age range 2-48 years) and 9 individuals with ankyloblepharon-ectodermal dysplasia-cleft lip/palate syndrome (0.5-60 years of age) by confocal laser scanning microscopy to determine their palmar sweat duct density and by quantification of pilocarpine-induced sweating. Genotype-phenotype correlations were assessed. In 12 of 23 patients (52%), a normal amount of sweat ducts was detected. These individuals (9 with ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome, 3 with ankyloblepharon-ectodermal dysplasia-cleft lip/palate syndrome) produced sufficient sweat volumes (≥ 20 μl) in response to pilocarpine. All other patients had clearly reduced sweating ability and fewer sweat glands, but no anhidrosis. Alteration of a specific proline residue (Pro590) of p63 was consistently linked to impaired perspiration.Conclusion: Hypohidrosis in p63-associated syndromes is less common and potentially less severe than previously thought and may be attributable to certain genotypes. What is Known: • Hypohidrosis which has been listed as a cardinal symptom of AEC and EEC syndromes may lead to life-threatening hyperthermia. What is New: • Patients with EEC and AEC syndromes often can sweat normally. • Hypohidrosis seems to be attributed to certain TP63 genotypes.

The p63 gene encodes a master regulator of epidermal commitment, development, and differentiation. Heterozygous mutations in the C-terminal domain of the p63 gene can cause ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome, a life-threatening disorder characterized by skin fragility and severe, long-lasting skin erosions. Despite deep knowledge of p63 functions, little is known about mechanisms underlying disease pathology and possible treatments. Here, we show that multiple AEC-associated p63 mutations, but not those causative of other diseases, lead to thermodynamic protein destabilization, misfolding, and aggregation, similar to the known p53 gain-of-function mutants found in cancer. AEC mutant proteins exhibit impaired DNA binding and transcriptional activity, leading to dominant negative effects due to coaggregation with wild-type p63 and p73. Importantly, p63 aggregation occurs also in a conditional knock-in mouse model for the disorder, in which the misfolded p63 mutant protein leads to severe epidermal defects. Variants of p63 that abolish aggregation of the mutant proteins are able to rescue p63\'s transcriptional function in reporter assays as well as in a human fibroblast-to-keratinocyte conversion assay. Our studies reveal that AEC syndrome is a protein aggregation disorder and opens avenues for therapeutic intervention.

Ankyloblepharon-ectodermal dysplasia-cleft lip/palate (AEC) syndrome is a disorder resulting from anomalous embryonic development of ectodermal tissues. There is evidence that AEC syndrome is caused by mutations in the TP63 gene, which encodes the p63 protein. This is an important regulatory protein involved in epidermal proliferation and differentiation.
Genome sequencing was performed in DNA from peripheral blood leukocytes of a newborn with AEC syndrome and her parents. Variants were searched in all coding exons and intron-exon boundaries of the TP63 gene.
A heterozygous missense variant (NM_003722.4:c.1063G>C (p.Asp355His) was found in the newborn patient. No variants were found in either of the parents.
We identified a previously unreported variant in TP63 gene which seems to be involved in the somatic malformations found in the AEC syndrome. The absence of this variant in both parents suggests that the variant appeared de novo.