S. Mallet

Prevalence of inherited ichthyosis in France: a study using capture-recapture method

BackgroundInherited ichthyoses represent a group of rare skin disorders characterized by scaling, hyperkeratosis and inconstant erythema, involving most of the tegument. Epidemiology remains poorly described. This study aims to evaluate the prevalence of inherited ichthyosis (excluding very mild forms) and its different clinical forms in France.MethodsCapture – recapture method was used for this study. According to statistical requirements, 3 different lists (reference/competence centres, French association of patients with ichthyosis and internet network) were used to record such patients. The study was conducted in 5 areas during a closed period.ResultsThe prevalence was estimated at 13.3 per million people (/M) (CI95%, [10.9 – 17.6]). With regard to autosomal recessive congenital ichthyosis, the prevalence was estimated at 7/M (CI 95% [5.7 – 9.2]), with a prevalence of lamellar ichthyosis and congenital ichthyosiform erythroderma of 4.5/M (CI 95% [3.7 – 5.9]) and 1.9/M (CI 95% [1.6 – 2.6]), respectively. Prevalence of keratinopathic forms was estimated at 1.1/M (CI 95% [0.9 – 1.5]). Prevalence of syndromic forms (all clinical forms together) was estimated at 1.9/M (CI 95% [1.6 – 2.6]).ConclusionsOur results constitute a crucial basis to properly size the necessary health measures that are required to improve patient care and design further clinical studies.

Expanding the clinical spectrum of hereditary fibrosing poikiloderma with tendon contractures, myopathy and pulmonary fibrosis due to FAM111B mutations

BackgroundHereditary Fibrosing Poikiloderma (HFP) with tendon contractures, myopathy and pulmonary fibrosis (POIKTMP [MIM 615704]) is a very recently described entity of syndromic inherited poikiloderma. Previously by using whole exome sequencing in five families, we identified the causative gene, FAM111B (NM_198947.3), the function of which is still unknown. Our objective in this study was to better define the specific features of POIKTMP through a larger series of patients.MethodsClinical and molecular data of two families and eight independent sporadic cases, including six new cases, were collected.ResultsKey features consist of: (i) early-onset poikiloderma, hypotrichosis and hypohidrosis; (ii) multiple contractures, in particular triceps surae muscle contractures; (iii) diffuse progressive muscular weakness; (iv) pulmonary fibrosis in adulthood and (v) other features including exocrine pancreatic insufficiency, liver impairment and growth retardation. Muscle magnetic resonance imaging was informative and showed muscle atrophy and fatty infiltration. Histological examination of skeletal muscle revealed extensive fibroadipose tissue infiltration. Microscopy of the skin showed a scleroderma-like aspect with fibrosis and alterations of the elastic network. FAM111B gene analysis identified five different missense variants (two recurrent mutations were found respectively in three and four independent families). All the mutations were predicted to localize in the trypsin-like cysteine/serine peptidase domain of the protein. We suggest gain-of-function or dominant-negative mutations resulting in FAM111B enzymatic activity changes.ConclusionsHFP with tendon contractures, myopathy and pulmonary fibrosis, is a multisystemic disorder due to autosomal dominant FAM111B mutations. Future functional studies will help in understanding the specific pathological process of this fibrosing disorder.

Epithelial barrier dysfunction in Desmoglein-1 deficiency

Desmoglein-1 deficiency is a missing link between impaired epithelial barrier function and immunological dysregulation. Our characterization of SAMEC syndrome highlighted the pivotal role of the desmoglein-1/ERBIN interaction as an inhibitor of skin inflammation via the NF-κB signaling pathway.

The scalp hair collar and tuft signs: A retrospective multicenter study of 78 patients with a systematic review of the literature

Background: Hair collar sign (HCS) and hair tuft of the scalp (HTS) are cutaneous signs of an underlying neuroectodermal defect, but most available data are based on case reports. Objective: We sought to define the clinical spectrum of HCS and HTS, clarify the risk for underlying neurovascular anomalies, and provide imaging recommendations. Methods: A 10‐year multicenter retrospective and prospective analysis of clinical, radiologic, and histopathologic features of HCS and HTS in pediatric patients was performed. Results: Of the 78 patients included in the study, 56 underwent cranial and brain imaging. Twenty‐three of the 56 patients (41%) had abnormal findings, including the following: (1) cranial/bone defect (30.4%), with direct communication with the central nervous system in 28.6%; (2) venous malformations (25%); or (3) central nervous system abnormalities (12.5%). Meningeal heterotopia in 34.6% (9/26) was the most common neuroectodermal association. Sinus pericranii, paraganglioma, and combined nevus were also identified. Limitations: The partial retrospective design and predominant recruitment from the dermatology department are limitations of this study. Conclusions: Infants with HCS or HTS are at high risk for underlying neurovascular anomalies. Magnetic resonance imaging scans should be performed in order to refer the infant to the appropriate specialist for management.

Caractéristiques cliniques et évolutives de la kératodermie aquagénique de l'enfant : étude rétrospective de 12 cas.

INTRODUCTION Aquagenic keratoderma (AK) is a rare condition characterized by wrinkled and edematous appearance of the skin of the hands occurring within minutes of immersion in water. Other than in a setting of cystic fibrosis, AK has rarely been reported in children, with only 13 clinical cases on record. Many clinicians are unfamiliar with AK and have fears relating to the association with cystic fibrosis The aim of this study is to describe the characteristics and to discuss management of the disease. METHODS Retrospective, multicentre study, including children aged under 16 years presenting AK. RESULTS 12 children were included. KA started at a mean age of 9.25 years (range: 20 months to 15 years). Clinical appearance and mode of onset were classical, with the palms being more severely affected than the soles. Pruritus or pain were reported in six cases. The median impact on daily life was 1.5/10. Some of the children underwent investigations: two had a negative sweat test, three had molecular analysis of the gene CFTR: one was negative and two had a heterozygote mutation. The course of the disease was variable: eight stabilizations, two exacerbations, one cure and one improvement. DISCUSSION This is the first series on childhood KA. Clinical characteristics were similar to those seen in adults. Impact was moderate and the disease course was variable. Systematic medical check-up for cystic fibrosis does not appear warranted in children since to date, cystic fibrosis has not been diagnosed in any patients presenting AK alone. CONCLUSION AK is rare in children and should not cause erroneous concern, and improvement can occur.

Pigmented macules of bony prominences (PMBP): A distinct presentation in patients with red hair.

6.62%, but not in the blood vessels or the epidermis of PWS lesions (Table I). The remaining 2 subjects were found to be negative for this mutation in all 4 dissected structures within the PWS lesions (Table I). There were no mutations found in normal control skin adjacent to the PWS sites or normal dermal blood vessels from a healthy subject (Table I). GNAQ (R183Q) induces minimal activation of MAPK in a cell culture system. Whether it can activate the same signaling pathway in PWS lesions remains incompletely understood. We recently found the c-Jun N-terminal kinases (JNK) and extracellular signal regulated kinases (ERK) were consecutively activated in both infantile and adult PWS blood vessels. Here we further identified that the GNAQ (R183Q) was primarily located within blood vessels in PWS lesions from 60% of our subjects, suggesting a causative correlation between GNAQ (R183Q) and activation of JNK and ERK in this subset of subjects under study. The reason for GNAQ (R183Q) occurrence in connective tissues and/or hair follicle/glands but not blood vessels in some subjects is unknown and requires further investigation. The fact that GNAQ (R183Q) occurs in both blood vessels and connective tissues suggests that pluripotent cells with the GNAQ (R183Q) may give rise to multilineages in PWS. We conclude that enrichment of GNAQ (R183Q) in PWS blood vesselsmay induce consecutive activation of JNK and ERK, thus contributing to the pathogenesis of PWS.