Heterozygous MAP3K20 variants cause ectodermal dysplasia, craniosynostosis, sensorineural hearing loss, and limb anomalies.

Biallelic pathogenic variants in MAP3K20, which encodes a mitogen-activated protein kinase, are a rare cause of split-hand foot malformation (SHFM), hearing loss, and nail abnormalities or congenital myopathy. However, heterozygous variants in this gene have not been definitively associated with a phenotype. Here, we describe the phenotypic spectrum associated with heterozygous de novo variants in the linker region between the kinase domain and leucine zipper domain of MAP3K20. We report five individuals with diverse clinical features, including craniosynostosis, limb anomalies, sensorineural hearing loss, and ectodermal dysplasia-like phenotypes who have heterozygous de novo variants in this specific region of the gene. These individuals exhibit both shared and unique clinical manifestations, highlighting the complexity and variability of the disorder. We propose that the involvement of MAP3K20 in endothelial-mesenchymal transition provides a plausible etiology of these features. Together, these findings characterize a disorder that both expands the phenotypic spectrum associated with MAP3K20 and highlights the need for further studies on its role in early human development.

Molecular Modeling Analysis Provides Genotype-Phenotype Correlation Insights in a Patient with Ankyloblepharon-Ectodermal Dysplasia-Clefting Syndrome.

Ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome is a rare autosomal dominant disorder. AEC is caused by mutations in the TP63 gene that encodes the tumor suppressor p63 protein, itself involved in the regulation of epidermal proliferation, development, and differentiation. We present here a typical AEC case of a four-year-old girl with extensive skin erosions and erythroderma of the scalp and the trunk, and to a lesser extent of the limbs, nail dystrophy on the fingers and toes, xerophthalmia, a high-arched palate, oligodontia, and hypohidrosis. Mutation analysis of the TP63 gene detected a de novo missense mutation in exon 14 (c.1799G>T; p.Gly600Val). We discuss the phenotype-genotype correlation by presenting the clinical features of AEC in the patient, and the effect of the detected mutation in p63 structure and function using protein structural modeling, in view of similar cases in the literature. We performed a molecular modeling study in order to link the effect on the protein structure level of the missense mutation G600V. We noted that the introduction of the bulkier Valine residue in place of the slim Glycine residue caused a significantly altered 3D conformational arrangement of that protein region, pushing away the adjacent antiparallel α helix. We propose that the introduced locally altered structure of the G600V mutant p63 has a significant functional effect on specific protein-protein interactions, thus affecting the clinical phenotype.

A rare case of aplasia cutis congenita.

In this study, we retrospectively analyzed the clinical data of a newborn with aplasia cutis congenita (ACC) to provide insights for diagnosing and treating the disease. It is believed that ACC with an intact skull and a skin defect diameter of less than 2 cm can be treated conservatively. The main strategies include local disinfection and regular dressing changes to promote epithelial regeneration. The lesion can heal over weeks or months through epithelization adjacent to the defect tissue, resulting in a healed contracture scar with a smooth, hairless surface that can be surgically removed later. For children with large scalp defects or skull defects, skin transplantation, free flap, and cranioplasty can be performed to repair the wound and restore the tissue structure. It is worth mentioning that although this child had a scalp defect larger than 2 cm, conservative treatment still had a significant effect. This suggests that conservative treatment can be considered as the first choice for ACC neonates without skull defects, and surgical treatment can be considered when necessary.

Aplasia Cutis Congenita With Cutaneous Meningioma: A Rare Case.

ABSTRACT: Cutaneous meningioma, characterized by ectopic meningothelial cells in the dermis or subcutis, is a rare neoplasm. Generally, the most common location for cutaneous meningioma is the scalp. We report a case of cutaneous meningioma presenting as soft, light red, atrophic, and smooth patches with central blue spots. On histological examination, the tumor consisted largely of epithelioid cells, whorls, nests, and syncytial sheets of meningothelial cells. HMB-45, Melan-A, and S100 were negative; epithelial membrane antigen and somatostatin receptor 2 were positive. Ultimately, histopathologic examination and immunohistochemistry results supported a diagnosis of cutaneous meningioma. In addition, dermal dysplasia was observed above the tumor, manifested by thinning of the dermis and loss of appendages. No abnormalities were found on brain magnetic resonance imaging. Cutaneous meningioma is an extremely rare tumor, and its manifestation as an atrophic patch is even rarer. There have been mainly clinical reports of cutaneous meningioma. This was a rare case of focal aplasia cutis congenita with cutaneous meningioma. For cutaneous meningioma to be diagnosed earlier, there needs to be greater public awareness about the condition.

A TP63 mutation identified in a Han Chinese family with ectodermal dysplasia.

OBJECTIVE: The purpose of this study was to identify a pathogenic mutation located in TP63 in a nuclear Han Chinese family. DESIGN: Whole-exome sequencing and Sanger sequencing were performed to identify candidate variants. The AlphaFold and PyMOL predicted the three-dimensional structure of the protein. Single-cell RNA-sequencing data and spatiotemporal transcriptomic atlas were used to generate the dissection of candidate gene expression at single-cell resolution. Significant genes (Pearson's coefficient ≥0.8 and P < 0.05) were identified for Gene Ontology (GO) analysis and Kyoto encyclopedia of genes and genomes (KEGG) pathways analysis. RESULTS: A heterozygous missense variant at TP63 exon 8 (c.1010 G>A:p.Arg337Gln) was identified in the proband. This variant was predicted deleterious and likely to impair the local stability of the protein. In addition, single-cell RNA-sequencing indicated that TP63 was highly expressed in skin tissues. Furthermore, spatial transcriptome data of mice embryos showed TP63 was mainly enriched in the mucosal epithelium, thymus, epidermis, mesenchyme, and surface ectoderm. GO and KEGG pathway annotation analysis revealed that TP63 played a positive role in the process of ectoderm via the TGF-beta signaling pathway. CONCLUSIONS: The missense variant of TP63 (c.1010 G>A:p.Arg337Gln) was associated with ectodermal dysplasia.

A novel variant in the GJB6 gene in a large Chinese family with a unique phenotype of Clouston syndrome.

Clouston syndrome (OMIM #129500), also known as hidrotic ectodermal dysplasia type 2, is a rare autosomal dominant skin disorder. To date, four mutations in the GJB6 gene, G11R, V37E, A88V, and D50N, have been confirmed to cause this condition. In previous studies, the focus has been mainly on gene sequencing, and there has been a lack of research on clinical manifestations and pathogenesis. To confirm the diagnosis of this pedigree at the molecular level and summarize and analyse the clinical phenotype of patients and to provide a basis for further study of the pathogenesis of the disease, we performed whole-exome and Sanger sequencing on a large Chinese Clouston syndrome pedigree. Detailed clinical examination included histopathology, hair microscopy, and scanning electron microscopy. We found a novel heterozygous missense variant (c.134G>C:p.G45A) for Clouston syndrome. We identified a new clinical phenotype involving all nail needling pain in all patients and found a special honeycomb hole structure in the patients' hair under scanning electron microscopy. Our data reveal that a novel variant (c.134G>C:p.G45A) plays a likely pathogenic role in this pedigree and highlight that genetic testing is necessary for the diagnosis of Clouston syndrome.

Obstetrical and neonatal outcomes of cardio-facio-cutaneous syndrome: Prenatal consequences of Ras/MAPK dysregulation.

We systematically delineated the prenatal phenotype, and obstetrical and neonatal outcomes of the RASopathy cardio-facio-cutaneous (CFC) syndrome. A comprehensive, retrospective medical history survey was distributed to parents of children with confirmed CFC in collaboration with CFC International, Inc. Data were collected on CFC gene variant, maternal characteristics, pregnancy course, delivery, and neonatal outcomes with the support of medical records. We identified 43 individuals with pathogenic variants in BRAF (81%), MEK1 (14%), or MEK2 (5%) genes. The median age was 8.5 years. Hyperemesis gravidarum, gestational diabetes, gestational hypertension, and preeclampsia occurred in 5/43 (12%), 4/43 (9%), 3/43 (7%), and 3/43 (7%) of pregnancies, respectively. Second and third trimester ultrasound abnormalities included polyhydramnios, macrocephaly, macrosomia, and renal and cardiac abnormalities. Delivery occurred via spontaneous vaginal, operative vaginal, or cesarean delivery in 15/42 (36%), 7/42 (16%), and 20/42 (48%), respectively. Median gestational age at delivery was 37 weeks and median birth weight was 3501 grams. Germline pathogenic vaiants had mutiple congenital consequences including polyhydramnios, renal and cardiac abnormalities, macrosomia, and macrocephaly on second and third trimester ultrasound. Elevated rates of operative delivery and neonatal complications were also noted. Understanding and defining a prenatal phenotype may improve prenatal prognostic counseling and outcomes.

A novel variant in the GJB6 gene in a large Chinese family with a unique phenotype of Clouston syndrome / 医学前沿

Clouston syndrome (OMIM #129500), also known as hidrotic ectodermal dysplasia type 2, is a rare autosomal dominant skin disorder. To date, four mutations in the GJB6 gene, G11R, V37E, A88V, and D50N, have been confirmed to cause this condition. In previous studies, the focus has been mainly on gene sequencing, and there has been a lack of research on clinical manifestations and pathogenesis. To confirm the diagnosis of this pedigree at the molecular level and summarize and analyse the clinical phenotype of patients and to provide a basis for further study of the pathogenesis of the disease, we performed whole-exome and Sanger sequencing on a large Chinese Clouston syndrome pedigree. Detailed clinical examination included histopathology, hair microscopy, and scanning electron microscopy. We found a novel heterozygous missense variant (c.134G>C:p.G45A) for Clouston syndrome. We identified a new clinical phenotype involving all nail needling pain in all patients and found a special honeycomb hole structure in the patients' hair under scanning electron microscopy. Our data reveal that a novel variant (c.134G>C:p.G45A) plays a likely pathogenic role in this pedigree and highlight that genetic testing is necessary for the diagnosis of Clouston syndrome.

Cutaneous squamous cell carcinoma in an autosomal-recessive Adams-Oliver syndrome patient with a novel frameshift pathogenic variant in the EOGT gene.

Aplasia cutis congenita (ACC) of the scalp and terminal transverse limb defects (TTLD) are the characteristic findings of Adams-Oliver syndrome (AOS). The variable clinical spectrum further includes cardiac, neurologic, renal, and ophthalmological findings. Associated genes in AOS are in the Notch and the CDC42/Rac1 signaling pathways. Both autosomal-dominant and autosomal-recessive inheritances have been reported, the latter with pathogenic variants in DOCK6 or EOGT. The EOGT-associated recessive type of AOS has been postulated to present a more favorable prognosis. We here report a 12-year-old girl from a refugee family of Iraq with consanguineous parents. She was born with a severe phenotype of AOS presenting a large ACC of the scalp with an underlying skull defect, which was often infected and inflamed. Afterward, additional ulceration developed. Furthermore, the girl showed microcephaly, TTLD on both hands and feet, and neurological findings: spastic paresis, epilepsy and suspicion of intellectual deficit. Molecular genetic analysis (next-generation sequencing) revealed a novel frameshift mutation in the EOGT gene in Exon 13 in homozygous constellation: c.1013dupA p.(Asn338Lysfs*24). A biopsy within an ulceration at the scalp ACC showed a cutaneous squamous cell carcinoma (cSCC) with local invasive growth into the dura, the meninges, and the cortex. Treatment including surgical resection and focal irradiation was not curative and the girl deceased 6 months after initial diagnosis. This report on a patient with AOS and an autosomal-recessive EOGT gene variant dying of a local aggressive cSCC at an ACC lesion shows that close monitoring of ACC is essential.

Dermoscopic characteristics of membranous aplasia cutis congenita: Report of 56 cases.

BACKGROUND: Membranous aplasia cutis congenita (MACC) presents at birth characterized by oval epidermis defect. Skin lesions with MACC have various clinic manifestations. In recent years, the usefulness of trichoscopy (scalp dermoscopy) has been reported for hair loss diseases. However, the dermoscopic features of MACC were mostly reported by case reports. OBJECTIVES: To summarized the obvious dermoscopic characteristics of MACC. MATERIALS & METHODS: These 56 cases met the clinical diagnostic criteria for MACC without forceps delivery complications or other birth injuries. To find the dermoscopic characteristics of MACC by summarizing 56 infants' dermoscopic pictures. RESULTS: The dermoscopic manifestation of MACC are characterized by hair follicle openings and hair deficiency in the center of skin lesions, translucent epidermis, hair root and hair bulb arranged along the margins of skin lesion. CONCLUSION: The typical dermoscopic characteristics of MACC could help clinicians to early diagnose and differential diagnosis.

Severe neuroglycopenic symptoms due to nonketotic hypoglycemia in children with cardio-facio-cutaneous syndrome.

Cardio-facio-cutaneous syndrome (CFC) (OMIM 115150) is a congenital disease caused by constitutive activation of the Raf/MEK/ERK signaling cascade. Unlike aspects of morphological anomalies, metabolic functions related to the disease have garnered little attention. We present severe neuroglycopenic symptoms due to nonketotic hypoglycemia in two children with CFC (Case 1, a 4-year-old male with c.389A > G heterozygous variant in MAP2K1; Case 2, a 3-year-old male with c.770A > G heterozygous variant in BRAF). Case 1 exhibited a nonketotic hypoglycemic coma and clustered left-hemispheric convulsions despite receiving infusion therapy, leading to severe sequelae with choreoathetosis. Brain magnetic resonance imaging of Case 1 showed T2-elongation with restricted diffusion on the bilateral basal ganglia and thalamus, with the dominance of the right putamen. Case 2 presented a prolonged generalized seizure as an initial clinical symptom but fully recovered. The presence of growth hormone and cortisol deficiency was ruled out in both cases. Blood spots acylcarnitine profiles excluded the co-occurrence of mitochondrial HMG-CoA synthase deficiency and HMG-CoA lyase deficiency. These cases demonstrate the potential vulnerability to nonketotic hypoglycemia, especially during lipid shortages. As children with CFC frequently have difficulties feeding, we suggest great attention should be paid to the potential risk of severe nonketotic hypoglycemia.

[A child with a bald spot on her scalp]. / Een baby met een kale plek op het hoofd.

A 6-month-old girl with an isolated bald spot was seen at the general practice. We diagnosed aplasia cutis congenita, a rare disorder with a wide variation in clinical symptoms. Most lesions can be managed conservatively. Larger defects, however, require surgery.

Confirmation of a Phenotypic Entity for TSPEAR Variants in Egyptian Ectodermal Dysplasia Patients and Role of Ethnicity.

Ectodermal dysplasia (ED) are hereditary disorders characterized by the disturbance of the ectodermal development of at least two of four ectodermal tissues: teeth, hair, nails and sweat glands. Clinical classification of ED is challenged by overlapping features, variable expressivity, and low number of patients, hindering full phenotypic spectrum identification. Disease-causing variants in elements of major developmental pathways, e.g., Ectodysplasin/NFκB, Wnt, and Tp63 pathways, have been identified in fewer than half of ED phenotypes. Whole-exome sequencing (WES) was performed for ten Egyptian ED patients presenting with tooth agenesis, normal sweating, scalp hypotrichosis, and sharing characteristic facial features. WES was followed by in silico analysis of the effects of novel detected genetic variants on mRNA and protein structure. The study identified four novel rare pathogenic and likely pathogenic TSPEAR variants, a gene which was recently found to be involved in ectodermal organogenesis. A novel in-frame deletion recurred in eight patients from six unrelated families. Comparing our cohort to previously reported TSPEAR cohorts highlighted the influence of ethnicity on TSPEAR phenotypic affection. Our study expands the clinical and mutational spectrum of the growing TSPEAR associated phenotypes, and pinpoints the influence of WES and in silico tools on identification of rare disease-causing variants.

Ttc30a affects tubulin modifications in a model for ciliary chondrodysplasia with polycystic kidney disease.

Skeletal ciliopathies (e.g., Jeune syndrome, short rib polydactyly syndrome, and Sensenbrenner syndrome) are frequently associated with nephronophthisis-like cystic kidney disease and other organ manifestations. Despite recent progress in genetic mapping of causative loci, a common molecular mechanism of cartilage defects and cystic kidneys has remained elusive. Targeting two ciliary chondrodysplasia loci (ift80 and ift172) by CRISPR/Cas9 mutagenesis, we established models for skeletal ciliopathies in Xenopus tropicalis Froglets exhibited severe limb deformities, polydactyly, and cystic kidneys, closely matching the phenotype of affected patients. A data mining-based in silico screen found ttc30a to be related to known skeletal ciliopathy genes. CRISPR/Cas9 targeting replicated limb malformations and renal cysts identical to the models of established disease genes. Loss of Ttc30a impaired embryonic renal excretion and ciliogenesis because of altered posttranslational tubulin acetylation, glycylation, and defective axoneme compartmentalization. Ttc30a/b transcripts are enriched in chondrocytes and osteocytes of single-cell RNA-sequenced embryonic mouse limbs. We identify TTC30A/B as an essential node in the network of ciliary chondrodysplasia and nephronophthisis-like disease proteins and suggest that tubulin modifications and cilia segmentation contribute to skeletal and renal ciliopathy manifestations of ciliopathies in a cell type-specific manner. These findings have implications for potential therapeutic strategies.

Ectodermal Dysplasia-Syndactyly Syndrome with Toe-Only Minimal Syndactyly Due to a Novel Mutation in NECTIN4: A Case Report and Literature Review.

Ectodermal dysplasia-syndactyly syndrome 1 (EDSS1) is characterized by cutaneous syndactyly of the toes and fingers and abnormalities of the hair and teeth, variably associated with nail dystrophy and palmoplantar keratoderma (PPK). EDSS1 is caused by biallelic mutations in the NECTIN4 gene, encoding the adherens junction component nectin-4. Nine EDSS1 cases have been described to date. We report a 5.5-year-old female child affected with EDSS1 due to the novel homozygous frameshift mutation c.1150delC (p.Gln384ArgfsTer7) in the NECTIN4 gene. The patient presents brittle scalp hair, sparse eyebrows and eyelashes, widely spaced conical teeth and dental agenesis, as well as toenail dystrophy and mild PPK. She has minimal proximal syndactyly limited to toes 2-3, which makes the phenotype of our patient peculiar as the overt involvement of both fingers and toes is typical of EDSS1. All previously described mutations are located in the nectin-4 extracellular portion, whereas p.Gln384ArgfsTer7 occurs within the cytoplasmic domain of the protein. This mutation is predicted to affect the interaction with afadin, suggesting that impaired afadin activation is sufficient to determine EDSS1. Our case, which represents the first report of a NECTIN4 mutation with toe-only minimal syndactyly, expands the phenotypic and molecular spectrum of EDSS1.

Late-onset eccrine syringofibroadenoma of the feet in a patient with hypohidrotic ectodermal dysplasia.

A 56-year-old woman with hypohidrotic ectodermal dysplasia presented with a 10-year history of persisting wart-like skin lesions on her feet. Biopsy revealed changes of eccrine syringofibroadenoma. These lesions are rare, with only nine case reports describing an association with ectodermal dysplasia of hidrotic type (Clouston and Schopf's syndrome). To our knowledge, this is the first case of eccrine syringofibroadenoma developing in the hypohidrotic/anhidrotic subtype of ectodermal dysplasia.

Enlarged spinal nerve roots in RASopathies: Report of two cases.

RASopathies are a group of genetic conditions caused by germline variants in genes encoding signal transducers and modulators of the RAS-MAPK cascade. These disorders are multisystem diseases with considerable clinical overlap, even though distinct hallmarks are recognizable for each specific syndrome. Here we report on the presence of enlarged spinal nerve roots resembling neurofibromas, a typical neuroradiological finding of neurofibromatosis type 1, in two patients with a molecularly confirmed diagnosis of Noonan syndrome and cardio-facio-cutaneous syndrome, respectively. This evidence add enlarged spinal nerve roots as features shared among RASopathies. Future studies aiming to a better understanding of the molecular mechanisms leading to neurogenic tumor development in these patients are necessary to define their biological nature, evolution, prognosis and possible treatments.