Clinical and molecular characteristics of autosomal recessive congenital ichthyosis in Thailand.

BACKGROUND: Autosomal recessive congenital ichthyosis (ARCI) is a heterogenous group of rare keratinization disorders. To date, more than 13 causative genes have been identified. However, data on clinical and molecular characteristics including genotype-phenotype correlation are lacking in Thailand. OBJECTIVE: We collected cases diagnosed with non-syndromic ARCI and syndromic recessive congenital ichthyosis at the Institute of Dermatology from 2011 to 2021 and performed genetic testing with next-generation sequencing and assessed clinical details. METHODS: Baseline demographic data, birth history, family history, skin manifestations at birth, current cutaneous manifestations, comorbidities, and response to treatments were assessed. DNA was screened for mutations using targeted gene sequencing of 45 genes related to congenital ichthyosis. RESULTS: A total of 33 patients were analyzed with an average age of 23.8 ± 13.9 years. Congenital ichthyosiform erythroderma (CIE) was most common (60.6%), followed by lamellar ichthyosis (18.2%), self-improving congenital ichthyosis (6.1%), Netherton syndrome (6.1%), ichthyosis prematurity syndrome (3%), Sjögren-Larsson syndrome (3%) and bathing suit ichthyosis (3%). Eight genes were found with pathogenic variants in our cohort as follows: ABCA12 42.4% (14/33), NIPAL4 24.2% (8/33), TGM1 15.2% (5/33), SPINK5 6.1% (2/33), ALDH3A2 3% (1/33), SLC27A4 3% (1/33), CYP4F22 3% (1/33), and ST14 3% (1/33). Clinically, 79% of patients with ABCA12 pathogenic variants in this study had CIE, 79% of w had novel biallelic pathogenic compound heterozygous variants, whereas 21% had homozygous missense variants. CONCLUSIONS: This is the first study to describe clinical and molecular findings of ARCI in a cohort from Thailand. Our findings demonstrate the clinical spectrum of the diseases and expand the molecular findings in a Southeast Asian population.

The Burden of Autosomal Recessive Congenital Ichthyoses on Patients and their Families: An Italian Multicentre Study.

Autosomal recessive congenital ichthyoses (ARCI) are characterized by generalized skin scaling, hyperkeratosis, erythroderma, and disabling features affecting the skin (palmoplantar keratoderma, fissures, pain, itch), eyes, ears, and joints. Disease severity and chronicity, patient disfigurement, and time and costs required for care impose a major burden on quality of life. This multicentre cross-sectional study investigated the impact of ARCI on quality of life of patients and families, using the Dermatology Life Quality Index (DLQI), the Children DLQI (CDLQI) and Family Burden of Ichthyosis (FBI) questionnaires. Disease severity was assessed by a dermatologist. A total of 94 patients were recruited, of whom 52 (55.3%) children. Mean age was 20.1 (median 13.5) years. The mean CDLQI/DLQI score was 7.8, and 21 patients scored >10, indicating a major impairment in quality of life: symptoms, feelings and treatment problems were the most affected domains of quality of life. FBI showed a major repercussion on psychological factors and work. The results of this study highlight the impact of ARCI on specific aspects of patient and family life, underlining the need for psychological support.

Molecular epidemiology of non-syndromic autosomal recessive congenital ichthyosis in a Middle-Eastern population.

Autosomal recessive congenital ichthyosis (ARCI) is a rare and heterogeneous skin cornification disorder presenting with generalized scaling and varying degrees of erythema. Clinical manifestations range from lamellar ichthyosis (LI), congenital ichthyosiform erythroderma (CIE) through the most severe form of ARCI, Harlequin ichthyosis (HI). We used homozygosity mapping, whole-exome and direct sequencing to delineate the relative distribution of pathogenic variants as well as identify genotype-phenotype correlations in a cohort of 62 Middle Eastern families with ARCI of various ethnic backgrounds. Pathogenic variants were identified in most ARCI-associated genes including TGM1 (21%), CYP4F22 (18%), ALOX12B (14%), ABCA12 (10%), ALOXE3 (6%), NIPAL4 (5%), PNPLA1 (3%), LIPN (2%) and SDR9C7 (2%). In 19% of cases, no mutation was identified. Our cohort revealed a higher prevalence of CYP4F22 and ABCA12 pathogenic variants and a lower prevalence of TGM1 and NIPAL4 variants, as compared to data obtained in other regions of the world. Most variants (89%) in ALOX12B were associated with CIE and were the most common cause of ARCI among patients of Muslim origin (26%). Palmoplantar keratoderma associated with fissures was exclusively a result of pathogenic variants in TGM1. To our knowledge, this is the largest cohort study of ARCI in the Middle-Eastern population reported to date. Our data demonstrate the importance of population-tailored mutation screening strategies and shed light upon specific genotype-phenotype correlations.

Unknown mutations and genotype/phenotype correlations of autosomal recessive congenital ichthyosis in patients from Saudi Arabia and Pakistan.

BACKGROUND: Autosomal recessive congenital ichthyosis (ARCI) is a genetically and phenotypically heterogeneous skin disease, associated with defects in the skin permeability barrier. Several but not all genes with underlying mutations have been identified, but a clear correlation between genetic causes and clinical picture has not been described to date. METHODS: Our study included 19 families from Saudi Arabia, Yemen, and Pakistan. All patients were born to consanguineous parents and diagnosed with ARCI. Mutations were analyzed by homozygosity mapping and direct sequencing. RESULTS: We have detected mutations in all families in five different genes: TGM1, ABCA12, CYP4F22, NIPAL4, and ALOXE3. Five likely pathogenic variants were unknown so far, a splice site and a missense variant in TGM1, a splice site variant in NIPAL4, and missense variants in ABCA12 and CYP4F22. We attributed TGM1 and ABCA12 mutations to the most severe forms of lamellar and erythematous ichthyoses, respectively, regardless of treatment. Other mutations highlighted the presence of a phenotypic spectrum in ARCI. CONCLUSION: Our results contribute to expanding the mutational spectrum of ARCI and revealed new insights into genotype/phenotype correlations. The findings are instrumental for a faster and more precise diagnosis, a better understanding of the pathophysiology, and the definition of targets for more specific therapies for ARCI.

Results of a nationwide epidemiologic survey of autosomal recessive congenital ichthyosis and ichthyosis syndromes in Japan.

BACKGROUND: Autosomal recessive congenital ichthyosis (ARCI) and ichthyosis syndrome (IS) are rare genetic skin disorders. OBJECTIVE: To estimate the number of patients with ARCI and IS in Japan and clarify the clinicoepidemiologic features of these diseases. METHODS: We performed a nationwide survey of patients treated for ARCI or IS during January 2005-December 2009. We developed diagnostic criteria and conducted a primary survey in a stratified random sample of Japanese hospitals to quantify the number of outpatients and inpatients with ARCI or IS. We performed a secondary survey of clinicoepidemiologic features in positive cases. RESULTS: The estimated number of patients receiving treatment for ARCI and IS during 2005-2009 was 220 (95% confidence interval [CI] 180-260). The estimated disease distribution was as follows: 95 (95% CI 80-110) patients with nonbullous congenital ichthyosiform erythroderma, 30 (95% CI 20-40) with lamellar ichthyosis, 15 (95% CI 10-20) with harlequin ichthyosis, and 85 (95% CI 50-120) with IS. LIMITATIONS: Patients with a mild case of the disease might not have visited a dermatology department, potentially causing underestimation of affected patients. CONCLUSION: We report the estimated number of patients with ARCI and IS in Japan and sex differences in the age distribution.

Spectrum of Autosomal Recessive Congenital Ichthyosis in Scandinavia: Clinical Characteristics and Novel and Recurrent Mutations in 132 Patients.

Autosomal recessive congenital ichthyosis (ARCI) represents a heterogeneous group of rare disorders of cornification with 3 major subtypes: harlequin ichthyosis (HI), lamellar ichthyosis (LI) and congenital ichthyosiform erythroderma (CIE). A 4th subtype has also been proposed: pleomorphic ichthyosis (PI), characterized by marked skin changes at birth and subsequently mild symptoms. In nationwide screenings of suspected cases of ARCI in Denmark and Sweden, we identified 132 patients (age range 0.1-86 years) classified as HI (n = 7), LI (n = 70), CIE (n = 17) and PI (n = 38). At birth, a collodion membrane or similar severe hyperkeratosis was reported in almost all patients with HI and LI, and in nearly half of patients with CIE and PI. Persistent ectropion was more common in HI (85%) and LI (57%), than in CIE (35%) and PI (5%). Anhidrosis was a frequent problem in all 4 groups (58-100%). A scoring (0-4) of ichthyosis/ery-thema past infancy showed widely different mean values in the subgroups: HI (3.2/3.1), LI (2.4/0.6), CIE (1.8/1.6), PI (1.1/0.3). Novel or recurrent mutations were found in 113 patients: TGM1 (n = 56), NIPAL4 (n = 15), ALOX12B (n = 15), ABCA12 (n = 8), ALOXE3 (n = 9), SLC27A4 (n = 5), CYP4F22 (n = 3), PNPLA1 (n = 1) and ABHD5 (n = 1). In conclusion, by performing a deep phenotyping and gene screening, ARCI can be definitely diagnosed in 85% of cases in Scandinavia, with a prevalence of 1:100,000 and > 8 different aetiologies.

Development of a disease severity score for newborns with collodion membrane.

BACKGROUND: Collodion membrane in the neonate may be the initial presentation of a number of different conditions. There is a lack of data correlating the extent of clinical involvement to the underlying disease and prognosis. OBJECTIVE: We sought to identify features predictive of the final outcome and complications in a cohort of patients with collodion membrane, using a disease severity score. METHODS: This was a retrospective cohort study of newborns with collodion membrane at a tertiary care institution over a period of 31 years. We designed and applied a 0- to 15-point severity score and correlated the results with the final diagnoses and complications. Data on demographics, membrane shedding, and treatment were collected. RESULTS: We identified 29 cases. Congenital ichthyosiform erythroderma and lamellar ichthyosis were the most common final diagnoses with 7 of 29 cases (24%) each; 3 patients were given the diagnosis of a syndromic ichthyosis. The classic nonsyndromic ichthyoses had higher average score results (7.33) than the syndromic ichthyoses (2.0) and other presentations (4.0), (P = .0097). Patients with major complications had higher, but nonsignificant, average severity scores (P = .64). LIMITATIONS: The retrospective design and small number of patients with a syndromic ichthyosis are limitations. CONCLUSIONS: Prospective studies are required to validate the proposed disease severity score.

Ictiosis congénitas autosómicas recesivas / Autosomal Recessive Congenital Ichthyosis

Las ictiosis congénitas autosómicas recesivas (ICAR) son trastornos infrecuentes de la queratinización que se engloban en las formas no sindrómicas de ictiosis. Clásicamente se distinguían en este grupo la ictiosis laminar (IL) y la eritrodermia ictiosiforme congénita (EIC). Actualmente se incluyen también la ictiosis arlequín, el bebé colodión autorresolutivo, el bebé colodión autorresolutivo acral y la ictiosis en traje de baño. Se ha estimado una prevalencia conjunta para IL y EIC de 1:138.000-1:300.000. En algunos países o regiones, como Noruega y la costa gallega, la prevalencia podría ser mayor debido a la existencia de efectos fundadores. Desde el punto de vista genético son muy heterogéneas. Seis genes se han asociado a estas entidades: TGM1, ALOXE3, ALOX12B, NIPAL4, CYP4F22 y ABCA12. En este trabajo se pretenden revisar los conocimientos actuales en el campo de las ICAR, incluyendo aspectos clínicos, histológicos, ultraestructurales, genético-moleculares y de tratamiento (AU)

The term autosomal recessive congenital ichthyosis (ARCI) refers to a group of raredisorders of keratinization classified as non syndromic forms of ichthyosis. This group was traditionally divided into lamellar ichthyosis (LI) and congenital ichthyosi form erythroderma (CIE)but today it also includes harlequin ichthyosis, self-healing collodion baby, acral self-healing collodion baby, and bathing suit ichthyosis.The combined prevalence of LI and CIE has been estimated at 1 case per 138 000 to 300 000population. In some countries or regions, such as Norway and the coast of Galicia, the prevalence may be higher due to founder effects. ARCI is genetically highly heterogeneous and has been associated with 6 genes to date: TGM1, ALOXE3, ALOX12B, NIPAL4, CYP4F22, and ABCA12. In this article, we review the current knowledge on ARCI, with a focus on clinical, histological, ultrastructural, genetic, molecular, and treatment-related aspects (AU)

Prevalence of autosomal recessive congenital ichthyosis: a population-based study using the capture-recapture method in Spain.

BACKGROUND: Previous reports on the prevalence of autosomal recessive congenital ichthyosis (ARCI) were based on single source data, such as lists of members in a patient association. These sources are likely to be incomplete. OBJECTIVES: We sought to describe the prevalence of ARCI. METHODS: We obtained data from 3 incomplete sources (dermatology departments, a genetic testing laboratory, and the Spanish ichthyosis association) and combined them using the capture-recapture method. RESULTS: We identified 144 living patients with ARCI. Of these, 62.5% had classic lamellar ichthyosis and 30.6% had congenital ichthyosiform erythroderma. The age distribution included fewer elderly patients than expected. The prevalence of ARCI in patients younger than 10 years, the best estimate as less subject to bias, was 16.2 cases per million inhabitants (95% confidence interval 13.3-23.0). According to the capture-recapture model, 71% of the patients were not being followed up in reference units, 92% did not have a genetic diagnosis, and 78% were not members of the ichthyosis association. LIMITATIONS: The prevalence of ARCI in Spain and findings related to the Spanish health care system might not be generalizable to other countries. CONCLUSIONS: The prevalence of ARCI is higher than previously reported. Many patients are not being followed up in reference units, do not have a genetic diagnosis, and are not members of a patient association, indicating room for improvement in their care. Data suggesting a reduced number of older patients might imply a shorter life expectancy and this requires further study.