Spectrum of phenotypic manifestations from a single point mutation of the p63 gene, including new cutaneous and immunologic findings

Novel missense mutation of the TP63 gene in a newborn with Hay-Wells/Ankyloblepharon-Ectodermal defects-Cleft lip/palate (AEC) syndrome: clinical report and follow-up

Introduction

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.

Patient’s presentation

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.

Ankyloblepharon-ectodermal Defects-cleft Lip-palate Syndrome Due to a Novel Missense Mutation in the SAM Domain of the TP63 Gene

Ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome is a rare genetic disease with an autosomal dominant transmission, characterized by several congenital anomalies. Clinical features include ectodermal defects affecting the skin, hair, teeth, nails and sweat glands, associated with typical eyelid fusion in addition to a cleft lip and/or palate. The diagnosis is based on clinical criteria and molecular genetic testing of TP63 gene, the gene related to AEC syndrome. In this context, most reported mutations induce an amino acid change in the sterile alpha motif (SAM) domain, and are predicted to disrupt protein-protein interactions. We here describe the case of a 2-year-old Moroccan girl diagnosed with AEC syndrome on the basis of clinical features. The molecular studies and bioinformatics tools revealed a novel heterozygous missense mutation c.1798G>C (p.Gly600Arg) in exon 14 of the TP63 gene, that was not found in her parents. The molecular analysis and the early diagnosis of this syndrome are important to offer appropriate genetic counseling and management to patients and their families.

Tooth agenesis and orofacial clefting: genetic brothers in arms?

Tooth agenesis and orofacial clefts represent the most common developmental anomalies and their co-occurrence is often reported in patients as well in animal models. The aim of the present systematic review is to thoroughly investigate the current literature (PubMed, EMBASE) to identify the genes and genomic loci contributing to syndromic or non-syndromic co-occurrence of tooth agenesis and orofacial clefts, to gain insight into the molecular mechanisms underlying their dual involvement in the development of teeth and facial primordia. Altogether, 84 articles including phenotype and genotype description provided 9 genomic loci and 26 gene candidates underlying the co-occurrence of the two congenital defects: MSX1, PAX9, IRF6, TP63, KMT2D, KDM6A, SATB2, TBX22, TGFα, TGFβ3, TGFβR1, TGFβR2, FGF8, FGFR1, KISS1R, WNT3, WNT5A, CDH1, CHD7, AXIN2, TWIST1, BCOR, OFD1, PTCH1, PITX2, and PVRL1. The molecular pathways, cellular functions, tissue-specific expression and disease association were investigated using publicly accessible databases (EntrezGene, UniProt, OMIM). The Gene Ontology terms of the biological processes mediated by the candidate genes were used to cluster them using the GOTermMapper (Lewis-Sigler Institute, Princeton University), speculating on six super-clusters: (a) anatomical development, (b) cell division, growth and motility, (c) cell metabolism and catabolism, (d) cell transport, (e) cell structure organization and (f) organ/system-specific processes. This review aims to increase the knowledge on the mechanisms underlying the co-occurrence of tooth agenesis and orofacial clefts, to pave the way for improving targeted (prenatal) molecular diagnosis and finally to reflect on therapeutic or ultimately preventive strategies for these disabling conditions in the future.

Differentially Expressed Genes in EEC and LMS Syndromes

Objectives

Ectrodactyly ectodermal dysplasia cleft lip/palate (EEC) syndrome and limb-mammary syndrome (LMS) share a similar phenotype and the same pathogenic gene, which complicates the ability to distinguish between these diagnoses. The current study aims to identify a potential and practical clinical biomarker to distinguish EEC from LMS.

Methods

Two EEC pedigrees and one LMS pedigree that have been previously reported were reanalyzed. After confirmation of the causative mutations for these new patients, whole-genome expression microarray analysis was performed to assess the molecular genetic changes in these families.

Results

Five new patients with classic symptoms were reported, and these individuals exhibited the same mutation as their relatives (c.812 G>C; c.611G>A; and c.680G>A). According to the whole genome expression results, the EEC patients exhibited different gene expression characteristics compared with the LMS patients. More than 5,000 genes were differentially expressed (changes >2 or <0.5-fold) among the EEC patients, LMS patients and healthy individuals. The top three altered pathways have been implicated in apoptosis, the hematopoietic cell lineage and the Toll-like receptor signaling pathway.

Conclusion

Our results provide additional clinical and molecular information regarding EEC and LMS and suggest that peripheral blood cytokines may represent a promising clinical biomarker for the diagnosis of these syndromes.

Ectodermal dysplasias: a clinical and molecular review

The ectodermal dysplasias are a large group of hereditary disorders characterized by alterations of structures of ectodermal origin. Although some syndromes can have specific features, many of them share common clinical characteristics. Two main groups of ectodermal dysplasias can be distinguished. One group is characterized by aplasia or hypoplasia of ectodermal tissues, which fail to develop and differentiate because of a lack of reciprocal signaling between ectoderm and mesoderm, the other has palmoplantar keratoderma as its most striking feature, with additional manifestations when other highly specialized epithelia are also involved. In recent decades, the genes responsible for at least 30 different types of ectodermal dysplasia have been identified, throwing light on the pathogenic mechanisms involved and their correlation with clinical findings.

A novel heterozygous point mutation in the p63 gene in a patient with ectodermal dysplasia associated with B-cell leukemia

We report a 7-year-old boy with a past medical history of B-cell leukemia with dysmorphic features, including cleft palate, hypotrichosis with trichorrhexis nodosa, hypohidrosis, oligodontia, and ridging of nails. A heterozygous germline mutation, Ala111Thr, in the p63 gene was detected in the boy and in his mother, who had no clinical expression. This case emphasizes the spectrum of different phenotypical manifestations of mutations in the p63 gene and underlines the possible role of this gene as a tumor suppressor.

A case of ankyloblepharon, ectodermal dysplasia, and cleft lip/palate syndrome with ectrodactyly: are the p63 syndromes distinct after all?

Ectodermal dysplasias are diseases with abnormal development of ectodermally derived tissues such as skin, hair, teeth, and nails. Mutations in the transcription factor p63 have been linked to several syndromes characterized by ectodermal, orofacial, and limb defects. We present the case of an infant with ankyloblepharon, cleft palate, scalp dermatitis, and ectrodactyly. She is unique for having a novel p63 mutation that has not been previously reported. Her case also points to the significant overlap between the p63-associated ectodermal dysplasias and challenges the traditional diagnostic schema for these rare syndromes.

ADULT syndrome caused by a mutation previously associated with EEC syndrome

Acro-Dermato-Ungual-Lacrimal-Tooth (ADULT) syndrome is a rare autosomal dominant syndrome characterized by ectrodactyly or syndactyly, excessive freckling and dry skin, dysplastic nails, lacrimal duct atresia, primary hypodontia and early loss of permanent teeth. ADULT syndrome is one of five such syndromes that result from mutations in TP63, encoding the transcription factor p63. Until now, only four families and three individuals with ADULT syndrome have been reported in the English literature. We present a 14-year-old female patient with ADULT syndrome and discuss phenotype-genotype correlations in the p63 syndromes.

Pathologic changes of skin and hair in ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome

Ankyloblepharon-Ectodermal defects-Cleft lip/palate (AEC) syndrome is a rare disorder of hair, skin, nails, and dentition caused by mutations in the p63 gene. Pathologic changes of skin and hair in AEC syndrome have previously been described in isolated case reports. Biopsies of normal and lesional skin from 19 patients with AEC syndrome were examined by light microscopy. Hair samples from 18 patients were examined by light and scanning electron microscopy. Histopathologic changes identified within the skin biopsies from clinically unaffected skin include mild atrophy, focal orthokeratosis, and mild superficial perivascular lymphocytic dermatitis. Scattered melanophages in the superficial and deep dermis likely reflect post-inflammatory change. One patient with a unilateral eruption of monomorphic papulopustules on the chest and shoulder demonstrated an acneiform intraepidermal pustule. Examination of the hair shafts revealed atrophy and loss of melanin pigment in some of the patients. Structural abnormalities included pili torti, pili trianguli et canaliculi, and irregular indentation and shallow grooves. Skin and hair findings in AEC syndrome were found to be generally similar to those described in other ectodermal dysplasia syndromes and corroborates the few prior descriptions in AEC syndrome specifically.

Hay-Wells syndrome in a child with mutation in the TP73L gene

Hay-Wells syndrome is a rare form of ectodermal dysplasia, also known as AEC syndrome (Ankyloblepharon filiforme adnatum, Ectodermal effects, Cleft lip/palate). It is inherited in an autosomal dominant fashion with variable expression, featuring congenital abnormalities of skin, hair, teeth, nail, eccrine and mucous glands. We present a three-month-old boy, born to unaffected parents, with typical clinical findings of AEC syndrome. In this boy, a mutation Ile537Thr (c.1610C>T) in the sterile alpha motive (SAM) domain of the TP73L (p63) gene was detected. Because of the broad spectrum of related syndromes such as Rapp-Hodgkin syndrome, Bowen-Armstrong syndrome, CHAND syndrome and epidermolysis bullosa hereditaria, the diagnosis of AEC should be base don both clinical findings and genetic analysis.

Cleft lip and palate repair in Hay-Wells/ankyloblepharon-ectodermal dysplasia-clefting syndrome

Hay-Wells/ankyloblepharon-ectodermal dysplasia-clefting syndrome is a rare autosomal dominant disorder characterized by ankyloblepharon, ectodermal dysplasia, and cleft lip and/or cleft palate. Mutations in the p63 gene recently have been shown to be etiologic in the majority of cases of ankyloblepharon-ectodermal dysplasia-clefting syndrome. To date, there have been no reports to document wound healing after cleft lip and/or palate repair in ankyloblepharon-ectodermal dysplasia-clefting patients. We describe two patients with ankyloblepharon-ectodermal dysplasia-clefting syndrome and provide a review of the literature. There have been no reported instances of wound healing complications in affected patients. Seventeen percent (3/18) of reported patients required revisions or repair of oronasal fistulae. Cleft lip and palate repair can be performed safely in patients with Hay-Wells syndrome.