Phenotypes, Genetics, and Estimated Prevalence of Focal Dermal Hypoplasia (Goltz Syndrome): A Single-Center Report.

BACKGROUND: Focal dermal hypoplasia (FDH), also known as Goltz syndrome, is a rare ectodermal dysplasia that primarily affects the skin, skeleton, and eyes. It is an X-linked dominant disorder, predominantly seen in females, caused by pathogenic variants in PORCN. METHODS: We characterized a case series of four genetically confirmed FDH patients (three females, one male) at Aarhus University Hospital, Denmark. We estimated the FDH prevalence from our local cohort and nationwide registry data. RESULTS: Three patients had characteristic dermatological findings suspicious for FDH and confirmed by targeted PORCN analysis. One patient had an atypical presentation with several malformations but only subtle skin changes and was diagnosed following trio exome-sequencing analysis. Skin atrophy with fat herniations and telangiectasias were typical cutaneous findings. Limb malformations included oligodactyly (cleft foot), syndactyly, and polydactyly. Eye abnormalities included coloboma and microphthalmos. Facial dysmorphology was defined by asymmetry, thin upper lip, and malformed ears. One patient developed a giant cell bone tumor, which is a rare feature of FDH. Dental findings included enamel hypoplasia with vertical grooving and irregular crowns. Four PORCN variants were identified, including three not previously reported in the literature.We estimated a regional point prevalence in Western Denmark of 1.6 cases per million population (95% confidence intervals (CI): 0.7-3.7 per million) and a nationwide registry-based point prevalence of 1.2 cases per million population (95% CI: 0.6-2.4 per million). CONCLUSIONS: FDH is an extremely rare and complex multisystem disorder of variable presentation, which requires close multidisciplinary collaboration for diagnosis and patient care.

Molecular and Cellular Function of p63 in Skin Development and Genetic Diseases.

The transcription factor p63 is a master regulator of multiple ectodermal derivatives. During epidermal commitment, p63 interacts with several chromatin remodeling complexes to transactivate epidermal-specific genes and repress transcription of simple epithelial and nonepithelial genes. In the postnatal epidermis, p63 is required to control the proliferative potential of progenitor cells, maintain epidermal integrity, and contribute to epidermal differentiation. Autosomal dominant sequence variant in p63 cause a spectrum of syndromic disorders that affect several tissues, including or derived from stratified epithelia. In this review, we describe the recent studies that have provided novel insights into disease pathogenesis and potential therapeutic targets.

Masticatory function in growing individuals with hypohidrotic ectodermal dysplasia: A longitudinal study.

BACKGROUND: Hypohidrotic ectodermal dysplasia (HED) is a hereditary disorder with agenesis of ectodermal derivatives, causing oligodontia or anodontia. Dentures are needed to improve the patients' mastication. AIM: This study aimed at preliminarily evaluating the masticatory function changes in Chinese individuals with HED after prosthetic rehabilitation from childhood to adolescence. DESIGN: This longitudinal study enrolled 10 HED patients. Data were collected during childhood and adolescence, respectively. The healthy children and adolescents were recruited as the control group. The surface electromyography (EMG) of masseter (MM) and anterior temporalis (TA) muscles during clenching and chewing were recorded. The EMG activity, asymmetry index (As), activity index (Ac), and chewing cycle were analyzed. The masticatory efficiency was measured by spectrophotometry with subjective masticatory ability assessed by a questionnaire. RESULTS: The EMG activities and masticatory efficiency of HED patients during childhood and adolescence were mostly lower with a higher As (p < .05). The chewing process enhanced the TA activity and balanced the As of HED adolescents (p > .05). The HED adolescents showed a more prevalent TA activity (p < .05). CONCLUSION: The masticatory function of the growing HED patients was functionally inferior to the dentate individuals with a narrowed gap from childhood to adolescence.

Facial Sebaceous Hyperplasia in an Adolescent With Hypohidrotic Ectodermal Dysplasia.

We report on a 13-year-old boy diagnosed with hypohidrotic ectodermal dysplasia (HED) due to a pathogenic variant in ectodysplasin A (EDA). He exhibited multiple whitish, millimetric papules clustered on the nasal ala, forehead, temporal, and zygomatic arch areas. Histological examination revealed numerous hyperplastic sebaceous lobules within the upper dermis. The occurrence of sebaceous papules in this distribution among HED patients has rarely been reported. An association with the blockage of the Wnt/ß-catenin pathway due to EDA malfunction has been speculated.

Genetic profiling and diagnostic strategies for patients with ectodermal dysplasias in Korea.

BACKGROUND: Ectodermal dysplasia (ED) is a rare genetic disorder that affects structures derived from the ectodermal germ layer. RESULTS: In this study, we analyzed the genetic profiles of 27 Korean patients with ED. Whole exome sequencing (WES) was performed on 23 patients, and targeted panel sequencing was conducted on the remaining 4 patients. Among the patients in the cohort, 74.1% (20/27) tested positive for ED. Of these positive cases, EDA and EDAR mutations were found in 80% (16/20). Notably, 23.1% (3/13) of EDA-positive cases exhibited copy number variations. Among the 23 patients who underwent WES, we conducted a virtual panel analysis of eight well-known genes, resulting in diagnoses for 56.5% (13/23) of the cases. Additionally, further analysis of approximately 5,000 OMIM genes identified four more cases, increasing the overall positivity rate by approximately 17%. These findings underscore the potential of WES for improving the diagnostic yield of ED. Remarkably, 94.1% of the patients manifesting the complete triad of ED symptoms (hair/skin/dental) displayed detectable EDA/EDAR mutations. In contrast, none of the 7 patients without these three symptoms exhibited EDA/EDAR mutations. CONCLUSIONS: When conducting molecular diagnostics for ED, opting for targeted sequencing of EDA/EDAR mutations is advisable for cases with classical symptoms, while WES is deemed an effective strategy for cases in which these symptoms are absent.

Peripheral giant cell granuloma in a child with ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome: a case report.

BACKGROUND: Ectrodactyly-ectodermal dysplasia-cleft lip/palate (EEC) syndrome mainly affects ectodermal and mesodermal tissues. It is usually manifested as split hands and feet, ectodermal dysplasia, and orofacial clefting, along with other signs and symptoms. A multidisciplinary approach to treatment is required, in which dentists play an important role in identifying and treating various oral conditions that may be genetically linked to or may be the result of EEC syndrome. CASE PRESENTATION: The present case describes the oral condition of a young child suffering from EEC syndrome and presenting with peripheral giant cell granuloma (PGCG) in the mandibular anterior region. After obtaining a thorough medical and family history and a clinical examination, the lesion was surgically excised under local anesthesia. The patient was followed up at periodic intervals for the next twenty four months, during which no recurrence of the lesion was observed. CONCLUSION: This report highlights the role of a dentist in the management of the oral conditions of patients suffering from EEC syndrome.

Prevalence rates for ectodermal dysplasia syndromes.

BACKGROUND: Ectodermal dysplasias (EDs) are a heterogeneous group of genetic conditions affecting the development and/or homeostasis of two or more ectodermal derivatives, including hair, teeth, nails, and certain glands. There are currently 49 recognized EDs with molecularly confirmed etiology. The EDs are very rare disorders, individually and in aggregate. Very little is published regarding the prevalence of these rare disorders. As a result of the genomics revolution, rare diseases have emerged as a global health priority. The various disabilities arising from rare disorders, as well as diagnostic and treatment uncertainty, have been demonstrated to have detrimental effects on the health, psychosocial, and economic aspects of families affected by rare disorders. Contemporary research methodologies and databases can address what have been historic challenges encountered when conducting research on rare diseases. OBJECTIVE: In this study, we aim to ascertain period prevalence rates for several of the more common ectodermal dysplasia syndromes, by querying a large multicenter database of electronic health records, Oracle Real-World Data. METHODS: For each of the included ectodermal dysplasia syndromes a clinical definition was developed by a committee of international experts with interests in EDs. The clinical definitions were based upon a combination of clinical features and designated by ICD-9 and ICD-10 codes. The January 2023 version of the Oracle Real-World Data database was queried for medical records that coincided with the clinical definitions. For our study, there were 64,523,460 individual medical records queried. RESULTS: Period prevalence rates were calculated for the following ED disorders: hypohidrotic ectodermal dysplasia, found to be 2.99 per 100,000; ectodermal dysplasia and immunodeficiency 1, 0.23 per 100,000; Clouston syndrome, 0.15 per 100,000; ectrodactyly ectodermal dysplasia and cleft lip/palate syndrome, 0.61 per 100,000; ankyloblepharon-ectodermal defects-cleft lip/palate syndrome, 0.36 per 100,000; focal dermal hypoplasia, 0.10 per 100,000; and incontinentia pigmenti, 0.88 per 100,000. CONCLUSION: This study established estimated period prevalence rates for several of the ectodermal dysplasia syndromes, and it demonstrated the feasibility of utilizing large multicenter databases of electronic health records, such as Oracle Real World Data.

Ectodermal dysplasia and cholesteatoma: A cross-sectional analysis of otologic issues.

OBJECTIVES: Previous studies have also associated cleft palate with increased cholesteatoma risk. Despite this close relation, the incidence of cholesteatoma and associated otologic issues in patients with ectodermal dysplasia types highly associated with cleft palate (EDT-ACPs) has not been formally analyzed. This study provides insight to guide clinicians caring for patients with ED types associated with cleft palate. METHODS: Individuals with TP63 disorders and Goltz syndrome/Focal Dermal Hypoplasia in the National Foundation for Ectodermal Dysplasia database were contacted for participation in an online REDCap survey from Sept-Dec '22. Descriptive statistics were generated using SAS JMP Pro 17 statistical software. RESULTS: 65 individuals participated in the survey (response rate approx. 18 %). The median [IQR] age was 22 [14, 43], 41 (63 %) were female, and Ectrodactyly-Ectodermal Dysplasia-Cleft Lip/Palate Syndrome (EEC) was most common (n = 26, 40 %). We found that, among our respondents with a history of cleft palate, the incidence of cholesteatoma was 39 %. Among respondents without a history of cleft palate, the incidence of cholesteatoma was 13 % CONCLUSIONS: Otologic issues, such as cholesteatoma, can have permanent implications including hearing loss that can be minimized by early identification and treatment. The estimated incidence of cholesteatoma among our participants is far above the estimated incidence of cholesteatoma in the general population with and without a history of cleft palate, suggesting an independent contribution of EDT-ACPs to the risk of cholesteatoma.

A Novel Ectodysplasin a Gene mutation of X-Linked Hypohidrotic Ectodermal Dysplasia.

Introduction: Hypohidrotic ectodermal dysplasia (HED) is a genetic disorder that influences structures of ectodermal origin, such as teeth, hair, and sweat glands. Compared with autosomal recessive and dominant modes of inheritance, the X-linked HED (XLHED) characterized by Hypodontia/Oligodontia teeth, Absent/sparse hair, Anhidrosis/hypohidrosis, and characteristic facial features, is the most frequent and its primary cause is the mutation of ectodysplasin A (EDA) gene. This research aimed to expound the clinical and molecular features of a Chinese male with XLHED and to summarize and compare several previous findings. Methods: Genomic DNA was obtained from the peripheral blood of the proband and his family members, then Sanger sequencing was used to perform a mutational analysis of EDA. Real-time quantitative PCR and Western blotting were used to detect EDA expression. The transcriptional activity of NF-κB was detected using a luciferase assay. Results: The probandwith XLHED was identified a novel EDA mutation, c.1119G>C(p.M373I), that affected the molecular analysis of transmembrane protein exon8 mutations, inherited from the mother. He showed a severe multiple-tooth loss, with over 20 permanent teeth missing and sparse hair and eyebrows, dry, thin, and itching skin. Furthermore, his sweating function was abnormal to a certain extent. Discussion: The functional study showed that this novel mutant led to a significant decrease in the EDA expression level and transcriptional activity of NF-κB. Our findings extend the range of EDA mutations in XLHED patients, which provides the basis and idea for further exploring the pathogenesis of XLHED.

Botanical extract combined with minoxidil improve hidrotic ectodermal dysplasia caused by p.G11R mutations: a case report.

PURPOSE: We aim to explore a potential treatment strategy for hair loss. MATERIALS AND METHODS: A male 6-year-old child was diagnosed with hidrotic ectodermal dysplasia 2 (HED2) caused by GJB6 (p.G11R) mutations. He presented at our clinic with diffuse thinning and fine and brittle hair since birth. Additionally, the child exhibited abnormal development of teeth, fingernails, and toenails. The condition of the child's hair had not improved significantly with age. He was treated with botanical extracts combined with Minoxidil. RESULTS: After one and a half months of treatment, the patient showed remarkable hair growth. CONCLUSIONS: Our team has previously used botanical extracts in combination for the treatment of autosomal recessive wooly hair in children. In the present case, treatment with botanical extract combined with minoxidil was found to be equally efficacious. This case report provides valuable information for future studies on the use of botanical extracts in treating hair loss, as well as a safe and effective potential treatment strategy for children with congenital alopecia.

Christ-Siemens-Touraine Syndrome: A Report of a Rare Pediatric Case.

Anhidrotic ectodermal dysplasia (AED), or Christ-Siemens-Touraine syndrome, is an X-linked recessive dermatosis. Rare in incidence, it affects 1 in 100,000 births, mostly boys. Through this observation, we detail the clinical signs that led us to suspect the diagnosis, how this pathology was confirmed, and the therapeutic management we carried out. We present a case of a 10-month-old boy presenting with altered manifestations affecting almost all the ectodermal structures like skin, hair, nails, teeth, sebaceous glands, sweat glands, and tear glands. He also had complete anodontia and a dry mouth. A multidisciplinary treatment was given to the patient with the collaboration of various health professionals. Although Christ-Siemens-Touraine syndrome is a rare condition, it is vital to recognize it early to improve care and prognosis for these patients, while mitigating the psychological impact of the condition on both children and parents.

Improving the Quality of Life in Patients With Hypohidrotic Ectodermal Dysplasia: A Holistic Approach.

Hypohidrotic ectodermal dysplasia (HED), often referred to as Christ-Siemens-Touraine syndrome, is an uncommon inherited genetic disorder characterized by irregularities in structures derived from the ectoderm, such as skin, hair, nails, teeth, and sweat glands. Common manifestations include thin hair, absent teeth (hypodontia) often pointed in shape, and diminished ability to sweat (hypohidrosis). Changes in the ectodysplasin A (EDA) gene are associated with the development of HED. Addressing this condition requires an integrated, interdisciplinary strategy to ensure the best possible support for individuals impacted. This case highlights the significance of early detection, collaborative care, and targeted interventions in managing HED. Continued research is crucial for creating novel therapies and enhancing life quality for those living with this rare condition. Here, we discuss a 22-year-old male patient displaying features such as hypodontia, sparse hair (hypotrichosis), irregular beard growth, a nasal deformity, and an inability to sweat (anhidrosis), which is associated with increased body temperature.

Ectodermal Dysplasia - An Overview and Update.

Ectodermal dysplasias are a heterogeneous group of disorders that are characterized by abnormal development of ectodermal structures like hair, teeth, nails, and sweat glands. Alhough they were earlier classified according to the structures affected and hence the clinical manifestations, recent developments inch towards a genetic basis for classification. They are currently divided into four groups of disorders based on the pathway involved, which includes the ectodysplasin/nuclear factor-kappa B (NFKB) pathway, wingless-type MMTV integration site family, member 10 ([wingless related integration site] WNT10), tumor protein p63 (TP63), and the structural group. In spite of attempts at the segregation of the various disorders, there is a great degree of overlap in clinical features among the conditions, which makes a thorough history-taking and clinical examination important in helping us arrive at a diagnosis and judge the various systems involved. A multidisciplinary approach forms the crux of the management of patients with ectodermal dysplasias and their families, with a focus on education, counseling, prosthesis, and an overall rehabilitative outlook. Special attention must also be paid to screening family members for varying severities of the disorders, and an attempt must be made at a genetic diagnosis with genetic counseling.

Like Father, Like Daughter - Ectodermal Dysplasia-Syndactyly Syndrome: A Case Report.

Ectodermal dysplasia-syndactyly syndrome 1 (EDSS1) is an exceedingly rare condition associated with mutations in the PVL4 gene. It is characterised by sparse, brittle hair, eyebrows and eyelashes, abnormal dentition and nails, along with bilateral cutaneous syndactyly involving the fingers and toes. We report a 2-year-old girl who presented to us with bilateral complete simple syndactyly of the third and fourth web spaces of the hands, along with bilateral syndactyly of both feet involving the second to fourth toes. Upon examination, sparse hair and eyebrows, along with abnormal dentition, were noted. Thorough clinical examination and genetic analysis were conducted on the affected child and her father, who exhibited similar clinical features. Genetic analysis revealed a homozygous nonsense mutation in the PVL4 gene in both individuals. According to the literature, EDSS1 has been reported in only 10 families worldwide, and there are no reported cases from India. Level of Evidence: Level V (Therapeutic).

Three-Dimensional Modeling and Quantitative Assessment of Mandibular Volume in Ectodermal Dysplasia: A Case Series.

Background and Objectives: Ectodermal dysplasia (ED)-a genetic disorder-is characterized by severe tooth deficiency. We compared the mandibular volume and the sagittal and horizontal mandibular widths between patients with ED (ED group) and individuals without tooth deficiency (control group) using three-dimensional modeling. We hypothesized that the mandibular volume differs in ED cases owing to congenital tooth deficiency. Materials and Methods: We used previously obtained cone-beam computed tomography (CBCT) images of 13 patients with ED. The control group data comprised retrospective CBCT images of patients of similar age and sex with a skeletal relationship of class 1. Further, using the three-dimensional image analysis software, the tooth crowns were separated from the mandible, the mandible was reconstructed and the gonion-to-gonion distance in the mandible was marked, the distance to the menton point was measured, and the distance between the two condyles was measured and compared with the control group. Results: Overall, 46.2% and 53.8% of the participants were men and women, respectively. In the ED group, the mean age of the participants was 15.46 (range, 6-24) years, and the mean number of mandibular teeth was 4.62. Notably, the edentulous mandible volume of the ED group (27.020 mm3) was statistically significantly smaller than that of the control group (49.213 mm3) (p < 0.001). There was no difference between the two groups in terms of the marked points. For data analysis, the Shapiro-Wilk test, independent samples t-test, and Mann-Whitney U test were used. Conclusions: It has been considered that mandible volume does not develop in ED cases because of missing teeth. Modern practices, such as the CBCT technique and three-dimensional software, may be effective in identifying the true morphologic features, especially in patients with genetic syndromes affecting the maxillofacial structure.

PRKD1-related telangiectasia-ectodermal dysplasia-brachydactyly-cardiac anomaly syndrome: Case report and review of the literature.

Telangiectasia-ectodermal dysplasia-brachydactyly-cardiac anomaly (TEBC) syndrome is a rare autosomal dominant condition, recently linked to the protein kinase D1 (PRKD1) gene. The phenotype of TEBC remains incomplete at this point. Our aim is to improve the characterization of the clinical and molecular aspects of the TEBC syndrome. We report on the 8th patient carrying a heterozygous de novo variation of PRKD1 c.2134G > A, p. (Val712Met) identified by trio exome sequencing. The proband presents with partial atrioventricular septal defect, brachydactyly, ectodermal dysplasia, telangiectasia that developed in childhood, intellectual disability with microcephaly, multicystic renal dysplasia and moderate hormonal resistance. In view of this 8th description and review of the literature, it appears that neurodevelopmental disorders and microcephaly are frequently associated with PRKD1 missense variants, adding to the four main clinical signs described initially in the TEBC syndrome. Further descriptions are required to confirm the observed endocrine and kidney abnormalities. This should contribute to a more comprehensive understanding of the phenotypic spectrum and may help establish genotype-phenotype correlations. In the context of genotype-first strategy, accurate patient descriptions are fundamental. Characterization of specific syndromic associations is essential for variant interpretation support and patient follow-up, even in very rare diseases, such as the TEBC syndrome.

Clinical presentation and genetics of tricho-rhino-phalangeal syndrome (TRPS) type 1: A single-center case series of 15 patients and seven novel TRPS1 variants.

Tricho-rhino-phalangeal syndrome (TRPS) is a rare malformation syndrome characterized by distinctive facial, ectodermal, and skeletal features. TRPS is divided into TRPS type I/III caused by pathogenic variants in TRPS1 and TRPS type II caused by contiguous gene deletions also spanning EXT1 and RAD21. Due to its rarity, knowledge of the clinical course of TRPS remains limited. Therefore, we collected and characterized a case series of 15 TRPS type I patients (median age at diagnosis 15 [interquartile range: 10-18] years, 11 females [73%]) seen at Aarhus University Hospital, Denmark, with a median follow-up period of 10 years. We estimated a minimum point prevalence of 0.5 in 100,000 (95% CI: 0.3-0.8 per 100,000) persons. Common craniofacial features included fine and sparse hair with a high anterior hairline, eyebrows with lateral thinning and a thicker medial part, prominent ears, a bulbous nose tip with small nasal alae, a low-hanging, and often wide columella, and a long philtrum with a thin upper vermillion. Specific skeletal features included short stature and deviating and short fingers with cone-shaped epiphyses and shortened metacarpals on radiographs. The most significant morbidity of the cohort was joint complaints, which were reported by all patients, often already before the TRPS diagnosis was established. We identified ten different TRPS1 variants including both frameshift/nonsense, missense, and splice-site variants, including seven variants not previously reported in the literature. In accordance with previous literature, no genotype-phenotype correlation was identified. The clinical trajectories were heterogeneous involving pediatrics, dermatology, orthopedic surgery, clinical genetics, and/or odontology, emphasizing that close multidisciplinary collaboration is essential for early diagnosis of TRPS and to ensure proper and timely patient care and counseling.

Dental implants in patients with ectodermal dysplasia: a computer guided quad zygomatic case report and literature review / Implantes dentales en pacientes con displasia ectodérmica: Reporte de caso y revisión de literatura

Abstract Ectodermal dysplasia (ED) is a genetic disorder affecting anatomical structures with an ectodermal origin. The consequent alveolar bone anomalies and lack of teeth require a multidisciplinary approach to rehabilitate patients function and esthetics. To avoid bone grafting procedures the application of zygomatic implants was suggested for the upper jaw treatment. The advancements in three-dimensional (3D) radiology and the introduction of digital implant planning software could enhance the approach to zygomatic implants in ED patients. The present case report describes the quad zygomatic implant treatment of the edentulous maxilla of an ED patient by means of computer guided implant surgery. The patient reported previous failure of bone grafting procedures in the upper jaw. The implants were immediately loaded with a screw-retained complete-arch resin prosthesis. The patient was followed up for 1 year with no biological nor mechanical complications reported, but a slight bone resorption in the anterior zone was observed. Zygomatic implants could be a potential alternative treatment to bone grafting in upper jaw and the digital implant planning could enhance the surgical procedure.

Resumen La displasia ectodérmica (DE) es una enfermedad genética que afecta las estructuras anatómicas de origen ectodérmico. Las consiguientes anomalías del hueso alveolar y la anodoncia requieren un planteamiento multidisciplinario para rehabilitar la función y la estética de los pacientes. Para evitar procedimientos de injerto óseo se sugirió la aplicación de implantes cigomáticos para el tratamiento del maxilar superior. Los avances en radiología tridimensional (3D) y la introducción de software de planificación de implantes digitales podrían mejorar el enfoque de los implantes cigomáticos en los pacientes con displasia ectodérmica. El presente reporte de caso describe el tratamiento con implantes cigomáticos en el maxilar superior edéntulo de un paciente con displasia ectodérmica mediante cirugía de implantes guiada por ordenador. El paciente refirió fracaso de procedimientos de injerto óseo en el maxilar superior. Los implantes se cargaron inmediatamente con una prótesis de resina de arcada completa. El paciente ha sido incluido en un programa de control postoperatorio por 1 año, sin reportarse complicaciones ni biológicas ni mecánicas, siendo el único problema encontrado una ligera reabsorción ósea en la zona anterior. Los implantes cigomáticos podrían ser un posible tratamiento alternativo al injerto óseo en el maxilar superior y la planificación de implantes digitales podría mejorar el procedimiento quirúrgico.

Punctal Atresia As a Clinical Indicator of Systemic Genetic Anomalies.

BACKGROUND: Punctal atresia or agenesis (PA) is a rare congenital anomaly characterized by the absence or closure of the tear duct puncta, potentially linked to systemic genetic anomalies. The necessity of a genetic workup based solely on the presence of PA remains uncertain. This study investigates a cohort of PA patients, examining the prevalence and types of associated syndromes. METHODS: A retrospective medical records review of all patients diagnosed with PA at the Children's Hospital of Philadelphia between 2009-2023 was conducted, analyzing medical histories and genetic testing results. Primary outcomes included the prevalence of systemic syndromes, while secondary outcomes focused on the variety of associated syndromes. RESULTS: Forty-four patients were included, of which 31 were male (70%) with a mean ± SD age 3.3 ± 3.3 years. Overall, 87 puncta in the study cohort were affected, and 26 cases (59%) were bilateral. Systemic abnormalities or genetic syndromes were identified in 19 patients (43%), with the most common being Ectodermal Dysplasia and Down syndrome. Additional rare syndromes were demonstrated. No significant association was found between systemic abnormalities and gender, bilaterality, or the number of puncta involved. CONCLUSIONS: A high incidence of systemic syndromes (43%) was observed in the study cohort. In individuals with PA who also exhibit extraocular disease, systemic evaluation and genetic workup should be considered. Syndromic diagnoses identified in our cohort also include: Branchio-oto-renal syndrome, 22q11.2 deletion syndrome, 1q21.1 microdeletion syndrome, NF1, monosomy 4q and trisomy 6q, which represent novel associations. The lack of correlation between PA's phenotypic severity and systemic abnormalities highlights the need to obtain a comprehensive medical history and consider a systemic workup in PA patients.

Tooth agenesis related to a novel KDF1 variant: A case report and literature review.

OBJECTIVES: To investigate the role of Keratinocyte Differentiation Factor 1 (KDF1) in ectodermal dysplasia (ED) and nonsyndromic tooth agenesis (NSTA) and perform a literature review. METHODS: Genome sequencing was used to identify genetic variants in a Thai, NSTA proband and validated through Sanger sequencing. Pathogenicity was assessed using ACMG guidelines, MetaRNN and AlphaMissense. A comprehensive review of KDF1/NSTA cases informed genotype-phenotype analysis of the proband. RESULTS: The proband revealed multiple missing teeth, caries and extensive periodontal disease. Deep phenotyping showed no signs of ED beyond tooth agenesis. The identified novel KDF1 variant, p.Ile243Leu, was classified as 'likely pathogenic' by ACMG and predicted as 'detrimental' by MetaRNN and AlphaMissense analyses. A total of 14 reviewed KDF1 cases revealed ED-associated variants (3 variants in 8 patients) clustering in the region of amino acids 251-275, within the DUF4656 domain, while NSTA-causing variants (4 variants in 6 patients) were typically found in amino- or carboxy-termini to this region. KDF1/NSTA cases exhibited an average of 15 missing teeth, with a higher prevalence in the mandible. CONCLUSION: This study identifies a novel KDF1 variant-related NSTA in Thai people. The genotype-phenotype correlates suggest a distinctive pattern and tooth agenesis of KDF1-related NSTA.