The association of Greig syndrome and mastocytosis reveals the involvement of the hedgehog pathway in advanced mastocytosis.

Mastocytosis is a heterogeneous disease characterized by an abnormal accumulation of mast cells (MCs) in 1 or several organs. Although a somatic KIT D816V mutation is detected in ∼85% of patients, attempts to demonstrate its oncogenic effect alone have repeatedly failed, suggesting that additional pathways are involved in MC transformation. From 3 children presenting with both Greig cephalopolysyndactyly syndrome (GCPS, Mendelian Inheritance in Man [175700]) and congenital mastocytosis, we demonstrated the involvement of the hedgehog (Hh) pathway in mastocytosis. GCPS is an extremely rare syndrome resulting from haploinsufficiency of GLI3, the major repressor of Hh family members. From these familial cases of mastocytosis, we demonstrate that the Hh pathway is barely active in normal primary MCs and is overactive in neoplastic MCs. GLI3 and KIT mutations had a synergistic, tumorigenic effect on the onset of mastocytosis in a GCPS mouse model. Finally, Hh inhibitors suppressed neoplastic MC proliferation in vitro and extend the survival time of mice with aggressive systemic mastocytosis (ASM). This work revealed, for the first time, the involvement of Hh signaling in the pathophysiology of mastocytosis and demonstrated the cooperative effects of the KIT and Hh oncogenic pathways in mice with ASM, leading to the identification of new promising therapeutic targets.

The challenging management of a series of 43 infants with Netherton syndrome: unexpected complications and novel mutations.

BACKGROUND: Netherton syndrome (NS) is a rare disease caused by SPINK5 mutations, featuring variable skin and hair involvement and, in many cases, allergic manifestations with a risk of lethality, particularly in infants. The clinical management of NS is challenging. OBJECTIVES: To analyse the clinical manifestations of a cohort of infants with NS managed in a reference centre and to draw up recommendations for management. METHODS: We conducted a monocentric analysis of patients with NS. The inclusion criteria were management in our reference centre, a histologically or molecularly confirmed diagnosis of NS and available epidemiological, clinical and laboratory data. RESULTS: A total of 43 patients with NS were included. Hypernatraemia was reported in 23 cases (54%) and associated with a greater likelihood of enteral and/or parenteral nutritional support (P < 0.001). Moreover, hypernatraemia was more frequent in patients with skin manifestations at birth (P = 0.026) and in patients bearing the c.153delT mutation in SPINK5 exon 3 (P = 0.014). The need for enteral and/or parenteral nutritional support was associated with a history of hypernatraemic dehydration (P < 0.001). Several unexpected extracutaneous complications were recorded, and new mutations were reported. The death rate (9% overall) was higher among the subset of patients bearing the c.153delT deletion. CONCLUSIONS: Our data emphasize that neonatal NS is a severe and sometimes lethal multisystem disorder. Patients have a high risk of variable metabolic anomalies (i.e. lethal hypernatraemia) and therefore have major nutritional needs. Cases of NS associated with c.153delT are particularly severe. Unexpected clinical manifestations broadened the phenotypic spectrum of NS. We provide recommendations on the management of the life-threatening manifestations of NS in neonates based on our multidisciplinary experience.

Management of albinism: French guidelines for diagnosis and care.

Albinism is a worldwide genetic disorder caused by mutations in at least 20 genes, identified to date, that affect melanin production or transport in the skin, hair and eyes. Patients present with variable degrees of diffuse muco-cutaneous and adnexal hypopigmentation, as well as ocular features including nystagmus, misrouting of optic nerves and foveal hypoplasia. Less often, albinism is associated with blood, immunological, pulmonary, digestive and/or neurological anomalies. Clinical and molecular characterizations are essential in preventing potential complications. Disease-causing mutations remain unknown for about 25% of patients with albinism. These guidelines have been developed for the diagnosis and management of syndromic and non-syndromic forms of albinism, based on a systematic review of the scientific literature. These guidelines comprise clinical and molecular characterization, diagnosis, therapeutic approach and management.

Development and co-construction of a therapeutic patient education program for albinism.

BACKGROUND: Long-term and ongoing support in accordance with the changing needs of patients and their families is one of the main components of patient care, including therapeutic patient education (TPE). OBJECTIVE: To co-construct a TPE program for albinism with all those involved in the management of albinism patients. METHODS: Eight steps have been defined for the co-construction process: 1) identify all the relevant experts and invite them to participate in the construction of a TPE program to improve care for and support of patients with albinism, 2) review and analyse all publications regarding TPE for albinism, 3) conduct semi-structured interviews with the patients' parents, 4) conduct brainstorming meetings with the participating experts for an exchange of experience and expertise, 5) elaborate the program's concrete content with the experts, 6) draw up a TPE skills checklist, 7) create TPE educational tools to facilitate learning, 8) review and summarize each step of the co-construction protocol. RESULTS: Co-construction of a TPE program for children, adolescents, and young adults with albinism, and their parents. CONCLUSION: Strengths and advantages of the co-construction process include: i) highlighting of the experiential knowledge mentioned in the repository, ii) multiplicity of points of view and perspectives, iii) rapid improvement in TPE training both for the association and the patients, iv) awareness of the shift caregivers' position with regards to TPE and recognition of the polysemy of their discourse. The TPE program for albinism has been authorized since 2018.

Genotypic and Phenotypic Analysis of 34 Cases of Inherited Junctional Epidermolysis Bullosa caused by COL17A1 Mutations.

Inherited epidermolysis bullosa defines a heterogeneous group of genodermatoses characterized by skin and/or mucosa fragility resulting in blistering. The junctional variant (JEB) is associated with mutations affecting the genes expressing the components of the dermo-epidermal junction (DEJ) [1-2]. We report 34 JEB patients with COL17A1 genetic mutations diagnosed in our Center between 1993 and 2019. Medical and biological records were collected with a standardized questionnaire.

Multidisciplinary consensus recommendations from a European network for the diagnosis and practical management of patients with incontinentia pigmenti.

BACKGROUND: Incontinentia pigmenti (IP) is a rare multisystemic X-linked dominant genetic disorder characterized by highly diagnostic skin lesions. The disease can be misdiagnosed in infants, and complications affecting the eyes and/or the brain can be severe. Our objective was to highlight the urgency of an appropriate diagnosis and management strategy, as soon as the first symptoms appear, and the need for a well-codified monitoring strategy for each child. METHODS: An in-depth literature review using a large number of databases was conducted. The selection criteria for articles were literature review articles on the disease, case series and retrospective studies based on the disease, clinical studies (randomized or not) on treatment, articles discussing patient care and management (treatment, diagnosis, care pathways), and recommendations. The research period was from 2000 until 2018. A group of multidisciplinary experts in IP management was involved, issued from different healthcare providers of the European Network for Rare Skin Diseases (ERN-Skin). The final recommendations have been submitted to two patient representative associations and to a general practitioner and a neonatal specialist prior to their finalization. RESULTS AND CONCLUSION: The diagnosis of IP must be promptly performed to detect potential extracutaneous manifestations, thus allowing the timely implementation of specific therapeutic and monitoring strategies. Eye involvement can be a therapeutic urgency, and central nervous system (CNS) involvement requires a very rigorous long-term follow-up. Assessments and patient support should take into account the possible co-occurrence of various symptoms (including motor, visual and cognitive symptoms).

[Off-label drugs in childhood psoriasis]. / Prescriptions hors AMM (autorisation de mise sur le marché) dans le psoriasis de l'enfant.

INTRODUCTION: Psoriasis affects 0.5% of children in Europe, with moderate to severe clinical forms in 15-35% of cases warranting the use of systemic treatments. Few treatments are licensed for childhood psoriasis. In this study, we analyzed the frequency of such prescriptions. MATERIALS AND METHODS: Our study was based on 3 retrospective cohort trials conducted in France between 2012 and 2018: χ-Psocar (313 children with psoriasis seen in hospitals), PsoLib (207 children seen in a private practice), and BiPe (134 children on biotherapies). Our evaluation was centered on off-label use. To avoid duplicates between cohorts, analysis focused on each cohort independently. RESULTS: In the χ-Psocar study, in 34.8% of cases, use of at least one off-label treatment, mainly topical vitamin D (36.0%), and systemic treatments (methotrexate and cyclosporine) was noted, on account of either the clinical type of psoriasis (13.7%) or patient age (24.6%). In the PsoLib study, in 41.5% of cases, at least one off-label treatment was noted, mainly combined calcipotriol-betamethasone (24.2%), ciclopirox shampoo (7.2%) and systemic treatments (n=20). The main reason was patient age (41.5%). In the BiPe study, in 97.0% of cases, at least one off-label treatment was noted. These prescriptions mainly concerned a combination of calcipotriol-betamethasone (68.7%) and tacrolimus (11.2%) along with systemic treatment comprising methotrexate, cyclosporin, methoxsalen or apremilast (n=125), but also biotherapies (n=85). The biotherapies were used off-label since at that time they had not yet been granted marketing authorisation. DISCUSSION: This study focused on 3 cohorts of children with psoriasis seen either in private practice or in a hospital setting, and it involved all types of treatment. Off-label prescriptions ranged from one-third to almost 100% of the children, depending on the individual cohorts. The prescribed drugs were topical treatments, conventional systemic drugs and biotherapies. Off-label prescription is not strictly prohibited in France provided it is within a well-defined regulatory framework. Where there is a rich bibliography, confident recommendations may be made. Unfortunately, in childhood psoriasis, the literature and recommendations are very limited, leaving prescribers with considerable individual responsibilities. Review of the license concerning children with psoriasis, a push to conduct therapeutic studies and the drafting of recommendations all appear necessary.

Management of congenital ichthyoses: European guidelines of care, part two.

These guidelines for the management of congenital ichthyoses have been developed by a multidisciplinary group of European experts following a systematic review of the current literature, an expert conference held in Toulouse in 2016, and a consensus on the discussions. These guidelines summarize evidence and expert-based recommendations and intend to help clinicians with the management of these rare and often complex diseases. These guidelines comprise two sections. This is part two, covering the management of complications and the particularities of some forms of congenital ichthyosis.

Dermatological manifestations in cardiofaciocutaneous syndrome: a prospective multicentric study of 45 mutation-positive patients.

BACKGROUND: Data on dermatological manifestations of cardiofaciocutaneous syndrome (CFCS) remain heterogeneous and almost without expert dermatological classification. OBJECTIVES: To describe the dermatological manifestations of CFCS; to compare them with the literature findings; to assess those discriminating CFCS from other RASopathies, including Noonan syndrome (NS) and Costello syndrome (CS); and to test for dermatological phenotype-genotype correlations. METHODS: We performed a 4-year, large, prospective, multicentric, collaborative dermatological and genetic study. RESULTS: Forty-five patients were enrolled. Hair abnormalities were ubiquitous, including scarcity or absence of eyebrows and wavy or curly hair in 73% and 69% of patients, respectively. Keratosis pilaris (KP), ulerythema ophryogenes (UO), palmoplantar hyperkeratosis (PPHK) and multiple melanocytic naevi (MMN; over 50 naevi) were noted in 82%, 44%, 27% and 29% of patients, respectively. Scarcity or absence of eyebrows, association of UO and PPHK, diffuse KP and MMN best differentiated CFCS from NS and CS. Oral acitretin may be highly beneficial for therapeutic management of PPHK, whereas treatment of UO by topical sirolimus 1% failed. No significant dermatological phenotype-genotype correlation was determined. CONCLUSIONS: A thorough knowledge of CFCS skin manifestations would help in making a positive diagnosis and differentiating CFCS from CS and NS.

Management of congenital ichthyoses: European guidelines of care, part one.

These guidelines for the management of congenital ichthyoses have been developed by a multidisciplinary group of European experts following a systematic review of the current literature, an expert conference held in Toulouse in 2016 and a consensus on the discussions. They summarize evidence and expert-based recommendations and are intended to help clinicians with the management of these rare and often complex diseases. These guidelines comprise two sections. This is part one, covering topical therapies, systemic therapies, psychosocial management, communicating the diagnosis and genetic counselling.

Dermatological manifestations in Noonan syndrome: a prospective multicentric study of 129 patients positive for mutation.

BACKGROUND: Data on dermatological manifestations of Noonan syndrome (NS) remain heterogeneous and are based on limited dermatological expertise. OBJECTIVES: To describe the dermatological manifestations of NS, compare them with the literature findings, and test for dermatological phenotype-genotype correlations with or without the presence of PTPN11 mutations. METHODS: We performed a large 4-year, prospective, multicentric, collaborative dermatological and genetic study. RESULTS: Overall, 129 patients with NS were enrolled, including 65 patients with PTPN11-NS, 34 patients with PTPN11-NS with multiple lentigines (NSML), and 30 patients with NS who had a mutation other than PTPN11. Easy bruising was the most frequent dermatological finding in PTPN11-NS, present in 53·8% of patients. Multiple lentigines and café-au-lait macules (n ≥ 3) were present in 94% and 80% of cases of NSML linked to specific mutations of PTPN11, respectively. Atypical forms of NSML could be associated with NS with RAF1 or NRAS mutations. In univariate analysis, patients without a PTPN11 mutation showed (i) a significantly higher frequency of keratinization disorders (P = 0·001), including keratosis pilaris (P = 0·005), ulerythema ophryogenes (P = 0·0001) and palmar and/or plantar hyperkeratosis (P = 0·06, trend association), and (ii) a significantly higher frequency of scarce scalp hair (P = 0·035) and scarce or absent eyelashes (P = 0·06, trend association) than those with PTPN11 mutations. CONCLUSIONS: The cutaneous phenotype of NS with a PTPN11 mutation is generally mild and nonspecific, whereas the absence of a PTPN11 mutation is associated with a high frequency of keratinization disorders and hair abnormalities.

Long-term evolving profile of childhood autoimmune blistering diseases: Retrospective study on 38 children.

BACKGROUND: Autoimmune bullous dermatoses (AIBDs) in children are uncommon, and their long-term evolution remains unknown. OBJECTIVE: The aim of this retrospective study was to characterize the long-term prognosis of AIBDs that started during childhood. METHODS: We conducted a monocentric retrospective study, in the French dermatology centre, by including all children affected by AIBDs. The long-term outcome was obtained through a phone call questionnaire. RESULTS: Sixty-three patients were included from January 1993 to December 2015, 34 female and 29 males: 27 Linear immunoglobulin A disease (LAD), 12 bullous pemphigoid (BP), 12 pemphigus, 8 herpetiform dermatitis (DH) and 4 epidermolysis bullosa aquisita (EBA). The mean age was 4.7 years old. Twenty-five patients were lost during the follow-up. For the 38 remaining patients, the mean follow-up duration for all pathologies was 6.6 years. Twenty-nine of them had at least one relapse. Late relapses were observed in two cases of DH and six cases of pemphigus (7-34 months). The mean treatment duration was 30.6 months with variability according to the AIBDs. Topical corticosteroids were used alone, effectively, for seven patients and in association with other treatment in 19 patients in complete remission. Complete remission was noted in 34/38 children with a follow-up of 4.4 years (0.08-19.5). The mean duration to complete remission was 30.5 months (6-114 months). Late nasal synechiae were reported in one EBA only. There was no significant associated comorbidity, but an association with a primary immune deficiency (PID) was observed in two cases. CONCLUSION: Childhood AIBDs appear to be of good overall prognosis but a long-term follow-up is mandatory, as relapses can be late, except for BP. The use of topical corticosteroids is frequently effective alone or in association. The association with PID leads to think about the possibility of a possible underlying dysimmunity in the child.

Biological treatments for paediatric psoriasis : a retrospective observational study on biological drug survival in daily practice in childhood psoriasis.

BACKGROUND: Three biotherapies - etanercept, adalimumab and ustekinumab - are licensed in childhood psoriasis. The few data available on their efficacy and tolerance are mainly derived from industry trials. However, biological drug survival impacts long-term performance in real-life settings. OBJECTIVE: The objective of this study was to evaluate the survival rates of biological therapies in children with psoriasis in real-life conditions. Secondary objectives were to evaluate the factors associated with the choice of the biological therapy and to report severe adverse events. MATERIALS AND METHODS: This study was an observational retrospective study. Data were extracted from the clinical records of 134 children. Kaplan-Meier estimates were used to analyse drug survival overall and in subgroups of plaque psoriasis, bio-naïve and non-naïve patients. RESULTS: We analysed 184 treatment courses: 70 with etanercept, 68 with adalimumab and 46 with ustekinumab. Factors associated with the choice of first-line biological agent were age at initiation (younger for adalimumab, P < 0.0001), age at onset of psoriasis (younger for adalimumab and etanercept, P = 0.03) and baseline Psoriasis Assessment Severity Index and Physician global assessment (both higher for adalimumab, P < 0.001). Drug survival rates were higher for ustekinumab than for adalimumab and etanercept (P < 0.0001) for all treatment and all psoriasis types, plaque-type psoriasis (P = 0.0003), patients naïve for biological agents (P = 0.0007) and non-naïve patients (P = 0.007). We reported eight serious adverse events (SAEs): severe infections (n = 3), significant weight gain (n = 2), psoriasis flare (n = 1) and malaise (n = 1). Biological therapy was discontinued in three children (one with psoriasis flare and two with weight gain). Only the two cases of weight gain resulted in an unfavourable outcome. CONCLUSIONS: Our real-life comparative study found that ustekinumab had the best drug survival outcome. The profile of SAEs in children was comparable to that in adults. These results will assist dermatologists in the decision-making process when choosing treatment options for children with psoriasis in daily practice.

Paediatric mastocytosis: long-term follow-up of 53 patients with whole sequencing of KIT. A prospective study.

BACKGROUND: Mastocytosis is a heterogeneous group of clinical disorders characterized by the abnormal accumulation of mast cells. The adult and paediatric forms differ in their clinical and genetic features and outcomes. OBJECTIVES: To describe the clinical evolution of a well-characterized cohort of paediatric mastocytosis (PM), and to analyse the relationship between KIT mutation and the clinical course. METHODS: This was a prospective cohort study performed at the National Clinical Reference Center for Mastocytosis. Diagnosis was confirmed by identification of KIT mutation on lesional skin biopsy. Mastocytosis subtype, mast cell mediator-related symptoms (MC MRS) and clinical course were recorded. Fifty-three patients with PM and > 4 years of disease course were enrolled. The mean ± SD age at the final evaluation was 13·2 ± 4·8 years. The main outcome was the type of KIT mutation as a predictor of evolution and clinical characteristics. RESULTS: Patients presented with maculopapular cutaneous mastocytosis (n = 44), diffuse cutaneous mastocytosis (n = 6) or mastocytoma (n = 3). The mean duration of disease was 12·1 years. Substantial or partial cutaneous regression (18 of 53 and 16 of 53), stabilization or aggravation (16 of 53) and complete cutaneous regression (three of 53) were noted. MC MRS mainly regressed (21 of 53). For 22 patients, evolution of MC MRS and evolution of cutaneous lesions were different. No significant association between evolution and KIT mutation or between evolution and type of cutaneous mastocytosis was found. A late onset of the disease (after 2 years) is associated with worse evolution. CONCLUSIONS: PM is not systematically self-regressive. MC MRS manifestations and cutaneous lesions can persist or increase overtime. KIT mutation is not a predictor of evolution.

Topical pimecrolimus for paediatric cutaneous mastocytosis.

BACKGROUND: Most cases of paediatric cutaneous mastocytosis (CM) occur before the age of 2 years, and regression occurs in only 67% of children. Given the absence of any specific therapy, CM is usually treated symptomatically. A few publications have reported the beneficial effect of calcineurin inhibitors for CM. AIM: We sought to evaluate the clinical effectiveness and safety profile of topical pimecrolimus cream for the treatment of CM. METHODS: We performed a retrospective study of all diagnosed cases of CM treated with topical pimecrolimus 1% cream between 2013 and 2015. All patients were evaluated in a paediatric dermatology unit of a tertiary medical centre. Epidemiological, clinical and treatment data, including effectiveness and safety, were reviewed. RESULTS: In total, 18 children (11 male, 7 female; age range 3-42 months) with CM were evaluated. Of the 146 treated lesions, 39 (26.7%) disappeared and 98 (67%) faded or developed postinflammatory hyperpigmentation. Of the 119 papular lesions, 24 (16.4%) showed partial flattening and 56 (47%) became macular. Darier sign became negative in 14 (82%) of 17 patients. No topical or systemic complications were observed. CONCLUSIONS: Topical therapy with pimecrolimus 1% cream should be considered in the treatment of CM.

Hydatidosis: Preparation and evaluation of radiolabeled antigens and antibodies.

The present preliminary study intends to evaluate the in vitro use of hydatid antigen and their antibodies once labeled with iodine 125(I125) and characterized from viewpoint of radiochemical purity and immunoreactivity. Radiolabelled molecules gave satisfactory purity of 94% and 96%-98%, for hydatid antigen and IgG respectively. As regards, the specific activity of these latter, varied between 4.79 and 5.97 µCi/µg. The specificity test of radiolabelled IgG against the hydatid membranes showed a significant recognition that increased proportionally according to the contact surface. Likewise this immunoreactivity test performed with a simple binding assay, using human hydatid fluid antigen (HHF-Ag), previously fixed on a solid phase, gave satisfactory fixation rate of the order of 356 ±â€¯48.08cpm, 2539 ±â€¯550.12cpm and 6558 ±â€¯712.76cpm for the concentrations of 0.1 µg/ml, 2 µg/ml and 25 µg/ml respectively. Statistical study of 88 sera, carried out with radiolabelled antigen (125I-HHF-Ag) in competitive radioimmunoassay test (CRIA) showed highly significant difference (p < 0.0001) in the binding capacity of antigens from patients sera with hydatid disease (65.63 ±â€¯9.12) compared to the negative sera (19.25 ±â€¯14.84). No cross reaction was observed using sera from patients with toxoplasmosis (33, 07 ±â€¯13, 07) and the difference was highly significant (p < 0.0001) compared to E granulosus infected patient sera. Furthermore, this test seemed to be sensitive since among the 43 sera tested, only 37 (86%) were found to be positive by passive hemagglutination (HAP), while the totality (100%) responded positively by CRIA. Our findings are encouraging, suggesting that these radiolabeled molecules could be useful for advancing toward new diagnostic and therapeutic modalities.

[Psoriatic arthritis in France, from infants to the elderly: Findings from two cross-sectional, multicenter studies]. / Rhumatisme psoriasique en France, du nourrisson à la personne âgée : données de deux études transversales multicentriques.

BACKGROUND: Psoriatic arthritis affects 20-30% of patients with psoriasis. Few epidemiological data are available in France about its prevalence and its association with skin lesions and comorbidities. OBJECTIVES: To assess the epidemiological aspects and the risk factors for psoriatic arthritis in children and adults in France. METHODS: Two cross-sectional studies were conducted in France in children (χ-Psocar, 23 pediatric dermatology centers belonging to the SFDP, 1 year) and adults (Resopsocar, 29 dermatology centers belonging to GEM RESOPSO, 4 months) to study the link between psoriasis and cardiovascular and metabolic comorbidities. RESULTS: Three hundred and thirteen children (males: 47.6%; mean age: 9.4 yrs) and 1,954 adults (males: 56.0%; mean age: 48.5 yrs) with psoriasis were included, with 4.2% of the children and 21.0% of the adults presenting psoriatic arthritis. Prevalence increased with age: 2.2% of children, 14.2% of adolescents, and over 20% after 40 years. It decreased after the age of 70 years (19.4%). Regardless of age, arthritis was not associated with gender. In the children's group, rheumatism was associated with nail involvement (P=0.04) and disease severity (P=0.0004). Adult rheumatism was associated with generalized plaque psoriasis (P=0.002), disease severity (P<0.0001), and obesity (P<0.0001). Localized plaque psoriasis was less often associated with arthritis (P<0.05). CONCLUSIONS: These two cross-sectional studies conducted in 2267 patients in France yielded information on the prevalence of joint involvement from infants to elderly subjects. It is the first study conducted in a single population to provide data for the whole population. Prevalence gradually increases with age, without gender difference, before decreasing in old age. We confirm the association of nail involvement in the first years of life, and of obesity in adults.

Dental and extra-oral clinical features in 41 patients with WNT10A gene mutations: A multicentric genotype-phenotype study.

WNT10A gene encodes a canonical wingless pathway signaling molecule involved in cell fate specification as well as morphogenetic patterning of the developing ectoderm, nervous system, skeleton, and tooth. In patients, WNT10A mutations are responsible for ectodermal-derived pathologies including isolated hypo-oligodontia, tricho-odonto-onycho-dermal dysplasia and Schöpf-Schulz-Passarge syndrome (SSPS). Here we describe the dental, ectodermal, and extra-ectodermal phenotypic features of a cohort of 41 patients from 32 unrelated families. Correlations with WNT10A molecular status (heterozygous carrier, compound heterozygous, homozygous) and patient's phenotypes were performed. Mild to severe oligodontia was observed in all patients bearing biallelic WNT10A mutations. However, patients with compound heterozygous mutations presented no significant difference in phenotypes compared with homozygous individuals. Anomalies in tooth morphology were frequently observed with heterozygous patients displaying hypodontia. No signs of SSPS, especially eyelids cysts, were detected in our cohort. Interestingly, extra-ectodermal signs consisted of skeletal, neurological and vascular anomalies, the latter suggesting a wider phenotypic spectrum associated with WNT10A mutations. Indeed, the Wnt pathway plays a crucial role in skeletal development, lipid metabolism, and neurogenesis, potentially explaining patient's clinical manifestations.