Inherited ichthyosis: Syndromic forms

Otological problems in ichthyosis: A literature review

BACKGROUND

Ichthyoses are a rare group of keratinization disorders characterized by scaling of the skin due to an impaired barrier function. Few studies have addressed ear involvement in patients with ichthyosis, although it is a probably underestimated aspect of the disease.

OBJECTIVE

This study aims to provide an overview of the otological manifestations in ichthyosis and propose specific treatment options.

METHODS

Articles were collected using PubMed, EMBASE, and Web of Science. A total of 53 articles were included in this literature review.

RESULTS

The most common ear problem in patients with ichthyosis is scale accumulation in the ear canals, which can lead to conductive hearing loss and increases the risk of ear infections. Furthermore, some types of ichthyosis are associated with outer ear malformations. Lastly, sensorineural hearing loss is common in syndromic forms of ichthyosis.

CONCLUSIONS

Otological problems are present in all types of ichthyoses and their treatment is challenging. The involvement of ear, nose, and throat specialists in the routine care of ichthyosis patients is essential for early identification and treatment of these manifestations. More research is needed to provide more insight into the otological problems in ichthyosis and to ameliorate treatment options.

Novel mutations of the ABCA12, KRT1 and ST14 genes in three unrelated newborns showing congenital ichthyosis

Background

Congenital ichthyosis (CI) is a heterogeneous group of genetic disorders characterized by generalized dry skin, scaling and hyperkeratosis, often associated to erythroderma. They are rare diseases, with overall incidence of 6.7 in 100,000. Clinical manifestations are due to mutations in genes mostly involved in skin barrier formation. Based on clinical presentation, CI is distinguished in non-syndromic and syndromic forms. To date, mutations of more than 50 genes have been associated to different types of CI.

Cases presentation

We report on three Italian unrelated newborns showing clinical signs compatible with different forms of CI of variable severity, namely Harlequin ichtyosis (HI), epidermolytic ichtyosis (EI) and autosomal recessive ichtyosis with hypotrichosis (ARIH). Target next generation sequencing (NGS) analysis identified three novel mutations of the ABCA12, KRT1 and ST14 genes, respectively associated to such congenital ichtyoses, not reported in literature. Genomic investigation allowed to provide the more appropriate management to each patient, based on an individualized approach.

Conclusions

Our report highlights the wide genetic heterogeneity and phenotypic variability of CI. It expands the current knowledge on such diseases, widening their genomic database, and providing a better clinical characterization. Furthermore, it underlines the clinical relevance of NGS, which is essential to address the management of patients. Indeed, it may guide towards the most adequate approach, preventing clinical obstinacy for subjects with more severe forms and unfavorable outcomes (together with the support, in such situations, of bioethicists included within the multidisciplinary care team), as well as reassuring families in those with milder course and favorable evolution.

New developments in the molecular treatment of ichthyosis: review of the literature

Ichthyosis covers a wide spectrum of diseases affecting the cornification of the skin. In recent years, new advances in understanding the pathophysiology of ichthyosis have been made. This knowledge, combined with constant development of pathogenesis-based therapies, such as protein replacement therapy and gene therapy, are rather promising for patients with inherited skin diseases. Several ongoing trials are investigating the potency of these new approaches and various studies have already been published. Furthermore, a lot of case series report that biological therapeutics are effective treatment options, mainly for Netherton syndrome and autosomal recessive congenital ichthyosis. It is expected that some of these new therapies will prove their efficacy and will be incorporated in the treatment of ichthyosis.

It's more than just lubrication of the skin: parents' experiences of caring for a child with ichthyosis

Background: The ichthyoses are a group of genetic skin disorders, characterized by excessive amounts of dry, thickened skin, which may be fragile, inelastic and prone to fissures and infection. Skin care is time consuming and demanding, and, usually performed by the parents.

Methods: We aimed to explore parental experience of caring for a child with ichthyosis, and collected data using semistructured interview, and thematic analysis.

Results: Our analysis revealed four main themes: Parents' and others' reactions to the child's difference, Experiences with healthcare services, It's all skin care, and Impact on relationships.

Conclusion: After birth of a child with severe ichthyosis, the parents experienced emotional distress and stigmatization due to the different appearance of the skin and healthcare professionals' lack of knowledge. Skin care caused pain in the child, was time consuming, and caused financial burdens. This study can guide healthcare professionals on where to focus future efforts in meeting the clinical and psychological needs of parents caring for a child with ichthyosis.

Proposal for a 6-step-approach for differential diagnosis of neonatal erythroderma

The broad differential diagnosis of neonatal erythroderma often poses a diagnostic challenge. Mortality of neonatal erythroderma is high due to complications of the erythroderma itself and the occasionally severe and life-threatening underlying disease. Early correct recognition of the underlying cause leads to better treatment and prognosis. Currently, neonatal erythroderma is approached by a case by case basis. The purpose of this scoping review was to develop a diagnostic approach in neonatal erythroderma. After a systematic literature search in Embase (January 1990 - May 2020, 74 cases of neonatal erythroderma were identified, and 50+ diagnoses could be extracted. Main causes were the ichthyoses (40%) and primary immunodeficiencies (35%). Congenital erythroderma was present in 64% (47/74) of the cases, predominantly with congenital ichthyosis (11/11; 100%), Netherton syndrome (12/14, 86%), and Omenn syndrome (11/23, 48%). Time until diagnosis ranged from 102 days to 116 days for cases of non-congenital erythroderma and congenital erythroderma respectively. Among the 74 identified cases a total of 17 patients (23%) died within a mean of 158 days and were related to Omenn syndrome (35%), graft versus host disease (67%), and Netherton syndrome (18%). Disease history and physical examination are summarized in this paper. Age of onset and a collodion membrane can help to narrow the differential diagnoses. Investigations of blood, histology, hair analysis, genetic analysis and clinical imaging are summarized and discussed. A standard blood investigation is proposed and the need for skin biopsies with Lympho-Epithelial Kazal-Type related Inhibitor-staining is highlighted. Overall, this review shows that diagnostic procedures narrow the differential diagnosis in neonatal erythroderma. A 6-step flowchart for the diagnostic approach for neonatal erythroderma during the first month of life is proposed. The approach was made with the support of expert leaders from international multidisciplinary collaborations in the European Reference Network Skin-subthematic group Ichthyosis.

Hearing loss in inherited metabolic disorders: A systematic review

Inherited metabolic disorders (IMDs) have been observed in individuals with hearing loss (HL), but IMDs are rarely the cause of syndromic HL. With early diagnosis, management of HL is more effective and cortical reorganization is possible with hearing aids or cochlear implants. This review describes relationships between IMDs and HL in terms of incidence, etiology of HL, pathophysiology, and treatment. Forty types of IMDs are described in the literature, mainly in case reports. Management and prognosis are noted where existing. We also describe IMDs with HL given age of occurrence of HL. Reviewing the main IMDs that are associated with HL may provide an additional clinical tool with which to better diagnose syndromic HL.

hiPSC-Derived Epidermal Keratinocytes from Ichthyosis Patients Show Altered Expression of Cornification Markers

Inherited ichthyoses represent a large heterogeneous group of skin disorders characterised by impaired epidermal barrier function and disturbed cornification. Current knowledge about disease mechanisms has been uncovered mainly through the use of mouse models or human skin organotypic models. However, most mouse lines suffer from severe epidermal barrier defects causing neonatal death and human keratinocytes have very limited proliferation ability in vitro. Therefore, the development of disease models based on patient derived human induced pluripotent stem cells (hiPSCs) is highly relevant. For this purpose, we have generated hiPSCs from patients with congenital ichthyosis, either non-syndromic autosomal recessive congenital ichthyosis (ARCI) or the ichthyosis syndrome trichothiodystrophy (TTD). hiPSCs were successfully differentiated into basal keratinocyte-like cells (hiPSC-bKs), with high expression of epidermal keratins. In the presence of higher calcium concentrations, terminal differentiation of hiPSC-bKs was induced and markers KRT1 and IVL expressed. TTD1 hiPSC-bKs showed reduced expression of FLG, SPRR2B and lipoxygenase genes. ARCI hiPSC-bKs showed more severe defects, with downregulation of several cornification genes. The application of hiPSC technology to TTD1 and ARCI demonstrates the successful generation of in vitro models mimicking the disease phenotypes, proving a valuable system both for further molecular investigations and drug development for ichthyosis patients.

A review of quality of life of patients suffering from ichthyosis

Introduction

Ichthyoses include a heterogeneous group of skin diseases often characterized by persistent scaling and hyperkeratosis with variable erythema, pruritus, and sweating impairment. The aim of our review was to assess the quality of life in patients with ichthyosis.

Methods

In July 2018 we performed a systematic search in the electronic database PubMed (MEDLINE). The MESH term “quality of life” was combined, through the Boolean operator AND with the key word “ichthyosis”. We considered eligible for the systematic review studies written in English.

Results

The literature search yielded 63 publications, but 7 studies were included in the review. Studies were published in 2003-2014 and involved a minimum of 10 and a maximum of 235 patients. Authors used 5 types of tools: Dermatology Life Quality Index (DLQI), Dermatitis Family Impact Questionnaire (DFI), Nottingham Health Profile (NHP) questionnaire, Short Form Questionnaire 36 and 12 (SF-36, SF-12). Many patients reported worse scores than general population. Patients referred physical problems related to pain (which negatively influenced the mobility).

Conclusions

Ichthyosis considerably impaired the QoL, especially for paediatric patients. Further studies and efforts should be done to manage and treat the pain.

Lipophagy and Lipolysis Status in Lipid Storage and Lipid Metabolism Diseases

This review discusses how lipophagy and cytosolic lipolysis degrade cellular lipids, as well as how these pathway ys communicate, how they affect lipid metabolism and energy homeostasis in cells and how their dysfunction affects the pathogenesis of lipid storage and lipid metabolism diseases. Answers to these questions will likely uncover novel strategies for the treatment of aforementioned human diseases, but, above all, will avoid destructive effects of high concentrations of lipids-referred to as lipotoxicity-resulting in cellular dysfunction and cell death.

Phenotypic suppression of acral peeling skin syndrome in a patient with autosomal recessive congenital ichthyosis

Autosomal recessive congenital ichthyosis (ARCI) manifests with generalized scaling often associated with generalized erythema. Mutations in at least 13 different genes have been reported to cause ARCI. Acral peeling skin syndrome (APSS) is a rare autosomal recessive disorder manifesting with peeling over the distal limbs and dorsal surfaces of hands and feet. APSS is mostly due to mutations in TGM5, encoding transglutaminase 5. Both ARCI and APSS are fully penetrant genetic traits. Here, we describe a consanguineous family in which one patient with mild ARCI was found to carry a homozygous mutation in ALOXE3 (c.1238G > A; p.Gly413Asp). The patient was also found to carry a known pathogenic homozygous mutation in TGM5 (c.1335G > C; p.Lys445Asn) but did not display acral peeling skin. Her uncle carried the same homozygous mutation in TGM5 but carried the ALOXE3 mutation in a heterozygous state and showed clinical features typical of APSS. Taken collectively, these observations suggested that the ALOXE3 mutation suppresses the clinical expression of the TGM5 variant. We hypothesized that ALOXE3 deficiency may affect the expression of a protein capable of compensating for the lack of TGM5 expression. Downregulation of ALOXE3 in primary human keratinocytes resulted in increased levels of corneodesmosin, which plays a critical role in the maintenance of cell-cell adhesion in the upper epidermal layers. Accordingly, ectopic corneodesmosin expression rescued the cell-cell adhesion defect caused by TGM5 deficiency in keratinocytes as ascertained by the dispase dissociation assay. The present data thus provide evidence for phenotypic suppression in a human hereditary skin disorder.

Clinical, etiopathogenic, and therapeutic aspects of KID syndrome

Keratitis-ichthyosis-deafness (KID syndrome) is a syndromes ichthyoses that is clinically and genetically heterogeneous requiring early and long-term multidisciplinary monitoring of affected individuals. A review of the clinical, etiopathogenic and therapeutic aspects is presented of this rare congenital ectodermal disorder.

Malnutrition in children with ichthyosis: Recommendations for monitoring from a multidisciplinary clinic experience

BACKGROUND

Short stature has been reported in congenital ichthyoses (CI), but few data exist on patients' nutritional status.

OBJECTIVE

To describe the nutritional status at the first evaluation of children and young adults with CI.

METHODS

Prospective observational study of patients assessed at a multidisciplinary clinic. Clinical variables and ichthyosis severity were collected. Anthropometric assessment was made by measuring weight and height, and nutritional status was classified based on the World Health Organization definitions for malnutrition. Analytical assessment included markers of nutritional status, fat-soluble vitamins, and micronutrients.

RESULTS

We included 50 patients with a median age of 5 years (IQR, 1.6-10.3). Undernutrition was found in 32% of patients, and 75% of the undernourished children presented growth impairment. Younger children and those with severe ichthyoses were the most affected. Micronutrient deficiencies were found in 60% of patients. Deficiencies of selenium (34%), iron (28%), vitamin D (22%), and zinc (4%) were the most frequent findings.

LIMITATIONS

Our small sample includes a heterogeneous group of ichthyoses.

CONCLUSION

Children with CI appear to be at risk of undernutrition, especially at younger ages. Nutritional deficiencies are common and should be monitored. Growth failure in children with ichthyosis could be caused by undernutrition and aggravated by nutritional deficiencies.

Epidermolytic hyperkeratosis: clinical update

Epidermolytic hyperkeratosis (EHK), earlier termed as bullous congenital ichthyosiform erythroderma is a skin disorder characterized as an autosomal dominant and rare disorder which has been observed to affect 1 in over 200,000 infants as a consequence of a significant mutation in the genes responsible for the keratin proteins, mostly keratin 1 and 10. The features present at birth include erythema and blistering. In adults, the hallmarks include hyperkeratosis, erosions, and blisters. The major symptoms including xerosis, pruritus, and painful fissuring lead not only to cosmetic problems but also stress, inferiority complex and other psychological conditions. While clinical inspection followed by confirmatory tests including histopathology and electron microscopic assessment is used for diagnosis, treatment modalities can be further improved for better diagnosis. This article reviews subtypes of ichthyosis, with a focus on EHK, genetics behind the disease, recently reported mutations, the existing diagnostics and treatments for the same and potential of new modalities in diagnosis/treatment.

Patients with congenital ichthyosis and TGM1 mutations overexpress other ARCI genes in the skin: Part of a barrier repair response?

Autosomal recessive congenital ichthyosis (ARCI) is a group of monogenic skin disorders caused by mutations in any of at least 12 different genes, many of which are involved in the epidermal synthesis of ω-O-acylceramides (acylCer). AcylCer are essential precursors of the corneocyte lipid envelope crosslinked by transglutaminase-1 (TGm-1), or a yet unidentified enzyme, for normal skin barrier formation. We hypothesized that inactivating TGM1 mutations will lead to a compensatory overexpression of the transcripts involved in skin barrier repair, including many other ARCI-causing genes. Using microarray, we examined the global mRNA expression profile in skin biopsies from five ARCI patients with TGM1 mutations and four healthy controls. There were a total of 599 significantly differentially expressed genes (adjusted P < 0.05), out of which 272 showed more than 1.5 log2fold-change (FC) up- or down-regulation. Functional classification of the latter group of transcripts showed enrichment of mRNA encoding proteins mainly associated with biological pathways involved in keratinocyte differentiation and immune response. Moreover, the expression of seven out of twelve ARCI-causing genes was significantly increased (FC = 0.98-2.05). Also, many of the genes involved in keratinocyte differentiation (cornified envelope formation) and immune response (antimicrobial peptides and proinflammatory cytokines) were upregulated. The results from the microarray analysis were also verified for selected genes at the mRNA level by qPCR and at the protein level by semi-quantitative immunofluorescence. The upregulation of these genes might reflect a compensatory induction of acylCer biosynthesis as a part of a global barrier repair response in the patient's epidermis.

Cross-sectional survey on disease severity in Japanese patients with harlequin ichthyosis/ichthyosis: Syndromic forms and quality-of-life analysis in a subgroup

BACKGROUND

Congenital ichthyoses (CIs) adversely affect quality of life (QOL) in patients. However, the effects of CIs on patient QOL have not been studied sufficiently.

OBJECTIVE

To investigate the association between disease severity and QOL in patients with harlequin ichthyosis (HI) and ichthyosis: syndromic forms (ISFs) METHODS: Clinical information of patients with HI and ISFs from 2010 to 2015 were obtained from 100 dermatology departments/divisions of principal institutes/hospitals throughout Japan. We examined the relationship between disease severity and QOL in patients with HI and ISFs. Patients who were aged 8 years or older and participated in a multicenter retrospective questionnaire survey in Japan were assessed by dermatology life quality index (DLQI, range of 0-30) and clinical ichthyosis score (range of 0-100).

RESULTS

Netherton syndrome patients had a significantly higher risk of allergy to food or environmental allergens than patients with other phenotypes. Keratitis-ichthyosis-deafness (KID) syndrome patients showed a significantly higher risk of skin infections than patients with other phenotypes. Complete data on DLQI were obtained from 13 patients, whose median age was 21 (8-71) years. Nine patients were male, and 4 were female. Systemic retinoids were administrated to 2 of the 3 HI patients. The Spearman's correlation coefficient between the clinical ichthyosis score and DLQI was 0.611 (P < 0.05).

CONCLUSION

We confirmed that Netherton syndrome and KID syndrome patients have a higher risk of allergy to food or environmental allergens and of skin infections, respectively. QOL impairment correlates with disease severity in HI and ISFs patients.

Whole-exome sequencing for diagnosis of hereditary ichthyosis

BACKGROUND

Hereditary ichthyosis constitutes a diverse group of cornification disorders. Identification of the molecular cause facilitates optimal patient care.

OBJECTIVE

We wanted to estimate the diagnostic yield of applying whole-exome sequencing (WES) in the routine genetic workup of inherited ichthyosis.

METHODS

During a 3-year-period, all ichthyosis patients, except X-linked and mild vulgar ichthyosis, consecutively admitted to a university hospital clinic were offered WES with subsequent analysis of ichthyosis-related genes as a first-line genetic investigation. Clinical and molecular data have been collected retrospectively.

RESULTS

Genetic variants causative for the ichthyosis were identified in 27 of 34 investigated patients (79.4%). In all, 31 causative mutations across 13 genes were disclosed, including 12 novel variants. TGM1 was the most frequently mutated gene, accounting for 43.7% of patients suffering from autosomal recessive congenital ichthyosis (ARCI).

CONCLUSION

Whole-exome sequencing appears an effective tool in disclosing the molecular cause of patients with hereditary ichthyosis seen in clinical practice and should be considered a first-tier genetic test in these patients.

Complex care of individuals with multiple sulfatase deficiency: Clinical cases and consensus statement

Multiple sulfatase deficiency (MSD) is an ultra-rare neurodegenerative disorder that results in defective sulfatase post-translational modification. Sulfatases in the body are activated by a unique protein, formylglycine-generating enzyme (FGE) that is encoded by SUMF1. When FGE is absent or insufficient, all 17 known human sulfatases are affected, including the enzymes associated with metachromatic leukodystrophy (MLD), several mucopolysaccharidoses (MPS II, IIIA, IIID, IVA, VI), chondrodysplasia punctata, and X-linked ichthyosis. As such, individuals demonstrate a complex and severe clinical phenotype that has not been fully characterized to date. In this report, we describe two individuals with distinct clinical presentations of MSD. Also, we detail a comprehensive systems-based approach to the management of individuals with MSD, from the initial diagnostic evaluation to unique multisystem issues and potential management options. As there have been no natural history studies to date, the recommendations within this report are based on published studies and consensus opinion and underscore the need for future research on evidence-based outcomes to improve management of children with MSD.

Clinical, biochemical, and genetic aspects of Sjögren-Larsson syndrome

Sjögren-Larsson syndrome (SLS) is caused by an autosomal recessive mutation in ALDH3A2, which encodes the fatty aldehyde dehydrogenase responsible for the metabolism of long-chain aliphatic aldehydes and alcohols. The pathophysiologic accumulation of aldehydes in various organs, including the skin, brain, and eyes, leads to characteristic features of ichthyosis, intellectual disability, spastic di-/quadriplegia, and low visual acuity with photophobia. The severity of the clinical manifestations thereof can vary greatly, although most patients are bound to a wheelchair due to contractures. To date, correlations between genotype and phenotype have proven difficult to document due to low disease incidence and high heterogenetic variability in mutations. This review summarizes the clinical characteristics of SLS that have been found to contribute to the prognosis thereof, as well as recent updates from genetic and brain imaging studies. In addition, the differential diagnoses of SLS are briefly illustrated, covering cerebral palsy and other genetic or neurocutaneous syndromes mimicking the syndrome.

Updated strategies for the management, pathogenesis and molecular genetics of different forms of ichthyosis syndromes with prominent hair abnormalities

Syndromic ichthyosis is rare inherited disorders of cornification with varied disease complications. This disorder appears in seventeen subtypes associated with severe systematic manifestations along with medical, cosmetic and social problems. Syndromic ichthyosis with prominent hair abnormalities covers five major subtypes: Netherton syndrome, trichothiodystrophy, ichthyosis hypotrichosis syndrome, ichthyosis hypotrichosis sclerosing cholangitis and ichthyosis follicularis atrichia photophobia syndrome. These syndromes mostly prevail in high consanguinity states, with distinctive clinical features. The known pathogenic molecules involved in ichthyosis syndromes with prominent hair abnormalities include SPINK5, ERCC2, ERCC3, GTF2H5, MPLKIP, ST14, CLDN1 and MBTPS2. Despite underlying genetic origin, most of the health professionals solely rely on phenotypic expression of these disorders that leads to improper management of patients, hence making these patients living an orphanage life. After dermal features, association of other systems such as nervous system, skeletal system, hair abnormalities or liver problems may sometimes give clues for diagnosis but still leaving place for molecular screening for efficient diagnosis. In this paper, we have presented a review of ichthyosis syndrome with prominent hair abnormalities, with special emphasis on their updated genetic consequences and disease management. Additionally, we aim to update health professionals about the practice of molecular screening in ichthyosis syndromes for appropriate diagnosis and treatment.

Ichthyosis linearis circumflexa with bamboo hair: challenges in the diagnosis and management

A 15-year-old boy had persistent and refractory erythroderma since early childhood. His parents noticed polycyclic skin lesions and hair fragility around the age of 5 years. He was treated by a local untrained practitioner for more than 3 years without any significant improvement, and he developed weight gain, thinning of skin, muscle weakness and growth retardation. He was evaluated in 2015 and found to have iatrogenic Cushing's disease with severe skeletal complications and pituitary-adrenal-gonadal suppression, which persisted despite gradual withdrawal of steroids.

Long term follow up of mucous membrane grafting for cicatricial ectropion in Ichthyosis: A case report

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In this case report we highlight briefly the unique entities of Icthyosis, the commonest ophthalmological manifestation and the reported modalities of surgical therapy, which includes Mucous Membrane Graft (MMG).

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Up to our knowledge this is the first reported long term follow up of MMG offered for Ichthyosis-related cicatricial ectropion.

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Thus we believe that this case has a value in using MMG as the standard therapy for a generalized condition, which is not peculiar only to ophthalmologists.

Introduction

Ichthyosis is a group of keratinizing diseases characterized by scaly and dry skin. One of the ocular complications associated with ichthyosis is cicatricial ectropion which often results in exposure keratopathy and eventually corneal scarring.

Presentation of case

In this report we are presenting a 21-year-old female who is known to have ichthyosis-related bilateral lower lid cicatricial ectropion, which was managed with Mucous Membrane Grafting (MMG) six years ago.

Discussion

Despite the serious complications of ichthyosis-related eyelid malposition such as cicatricial ectropion, until present no single way has been standardized to treat the ectropion in these patients. MMG has been previously described, but up to our knowledge this is the first reported long term follow up of MMG offered for ichthyosis-related cicatricial ectropion.

Conclusion

We strongly recommend MMG as a promising surgical treatment option offered for ichthyosis patients with cicatricial ectropion providing good outcome and acceptable cosmetic results.