Updated mutational spectrum and genotype-phenotype correlations in ichthyosis patients with ABCA12 pathogenic variants.

Autosomal recessive congenital ichthyoses (ARCI) is a genetically heterogeneous condition that can be caused by pathogenic variants in at least 12 genes, including ABCA12. ARCI mainly consists of congenital ichthyosiform erythroderma (CIE), lamellar ichthyosis (LI) and harlequin ichthyosis (HI). The objective was to determine previously unreported pathogenic variants in ABCA12 and to update genotype-phenotype correlations for patients with pathogenic ABCA12 variants. Pathogenic variants in ABCA12 were detected using Sanger sequencing or a combination of Sanger sequencing and whole-exome sequencing. To verify the pathogenicity of a previously unreported large deletion and intron variant, cDNA analysis was performed using total RNA extracted from hair roots. Genetic analyses were performed on the patients with CIE, LI, HI and non-congenital ichthyosis with unusual phenotypes (NIUP), and 11 previously unreported ABCA12 variants were identified. Sequencing of cDNA confirmed the aberrant splicing of the variant ABCA12 in the patients with the previously unreported large deletion and intron variant. Our findings expand the phenotype spectrum of ichthyosis patients with ABCA12 pathogenic variants. The present missense variants in ABCA12 are considered to be heterogenous in pathogenicity, and they lead to varying disease severities in patients with ARCI and non-congenital ichthyosis with unusual phenotypes (NIUP).

Ophthalmic Review on Neonatal Harlequin Ichthyosis.

Harlequin ichthyosis is a rare congenital autosomal recessive disorder that causes hyperkeratosis or plate-like keratosis. Hyperkeratosis affects both upper and lower eyelids and causes defective eyelids. Lagophthalmos and persistent dry eye will cause desiccation of the cornea, possibly leading to complications such as ectropion, cornea ulceration, corneal perforation, etc. Harlequin ichthyosis requires regular ocular review to prevent ocular complications. In this child, he was born with defective eyelids, but subsequent management prevented the complications mentioned. This is a case of harlequin ichthyosis in a neonate from an ophthalmological point of view.

A Unique Case of Harlequin Ichthyosis in the Tertiary Health Care System in a Rural Area.

Harlequin ichthyosis (HI) is a severe and rare genetic anomaly that affects skin development and leads to the formation of thick, diamond-shaped plates of keratinized skin. The adenosine triphosphate binding cassette A 12 (ABCA12) gene, which is essential for the transportation of lipids required for the skin's barrier function, has mutations that result in this condition. The affected individuals exhibit distinct clinical features, including thickened skin, deep cracks, and fissures, which can result in significant physical and functional impairments. HI is usually apparent at birth, with affected infants presenting with tight and rigid skin that restricts movement and normal growth. The condition is associated with various complications, including difficulty breathing, feeding difficulties, and increased susceptibility to infections. Due to the impaired skin barrier, affected individuals are also prone to dehydration and temperature dysregulation. In this case report, we present a unique case of ichthyosis in a nine-month-old child. Despite advances in medical care, HI remains a challenging condition with a high mortality rate, particularly in the neonatal period. However, with early detection, appropriate interventions, and an improved understanding of the underlying molecular mechanisms, there is hope for enhanced management and improved quality of life for individuals living with HI.

Partial Loss of Function ABCA12 Mutations Generate Reduced Deposition of Glucosyl-Ceramide, Leading to Patchy Ichthyosis and Erythrodermia Resembling Erythrokeratodermia Variabilis et Progressiva (EKVP).

Ichthyoses are genetically determined cornification disorders of the epidermis characterized by the presence of different degrees of scaling, hyperkeratosis, and erythroderma often associated with palmoplantar keratoderma. Different classifications of these diseases have been proposed, often based upon the involved genes and/or the clinical presentation. The clinical features of these diseases present some overlap of phenotypes among distinct genetic entities, depending mainly on the penetrance of mutations. In this study, using a clinical, genetic, and molecular approach, we analyzed a family with two affected members who had clinical and histological features resembling erythrokeratodermia variabilis (EKV) or a type of erythrodermic hyperkeratosis with palmoplantar keratoderma. Despite of the clinical presentation, we demonstrated that the affected patients were genetically double heterozygous for two different mutations in the ABCA12 gene, known to be responsible for harlequin ichthyosis. To explain the mild phenotype of our patients, we performed a molecular characterization of the skin. In the upper layers of the epidermis, the results showed a patchy presence of the glucosyl-ceramides (GlcCer), which is the lipid transported by ABCA12, fundamental in contributing to skin impermeability. Indeed, the two mutations detected do not completely abolish ABCA12 activity, indicating that the mild phenotype is due to a partial loss of function of the enzyme, thus giving rise to an intermediate phenotype resembling EKVP, due to a partial depletion of GlcCer deposition.

Assessing the Use of Ustekinumab in a Pediatric Patient With Harlequin Ichthyosis.

Harlequin ichthyosis (HI) is a rare, life-threatening genodermatosis that is characterized by thick, scaly, hyperkeratotic plaques throughout the skin and is typically associated with severe ectropion, eclabium, flexion contractures, and dysplastic ears. HI is thought to be caused by a loss-of-function mutation in the ABCA12 gene. It has traditionally been thought to be difficult to treat, as there are currently no treatments available that are approved by the Food and Drug Administration (FDA). We present a case of a 15-year-old boy with HI and a complex medical history who was treated with a trial of off-label ustekinumab. There was an initial mild improvement in his erythema within one month of treatment, but by his one-year follow-up, ustekinumab had failed to produce a significant treatment response and was, thus, discontinued from his regimen. This case report highlights that although ustekinumab may be a viable treatment option for other ichthyotic entities, more research is needed to evaluate its clinical safety and efficacy in treating pediatric patients with HI.

Case Report: Novel rare mutation c.6353C > G in the ABCA12 gene causing harlequin ichthyosis identified by whole exome sequencing.

Background: Harlequin ichthyosis (HI) is a severe rare genetic disease that mainly affects the skin. Neonates with this disease are born with thick skin and large diamond-shaped plates covering most of their bodies. Affected neonates lose the ability to control dehydration and regulate temperature and are more susceptible to infections. They also face respiratory failure and feeding problems. These clinical symptoms are factors associated with high mortality rates of neonates with HI. Until now, there are still no effective treatments for HI patients and most patients die in the newborn period. Mutation in the ABCA12 gene, which encodes an adenosine triphosphate-binding cassette (ABC) transporter, has been demonstrated as the major cause of HI. Case presentation: In this study, we report the case who is one infant that was born prematurely at 32 gestational weeks with the whole body covered with thick plate-like scales of skin. The infant was severely infected with mild edema, multiple cracked skins full of the body, yellow discharge, and necrosis of fingers and toes. The infant was suspected to be affected by HI. Whole exome sequencing (WES) was performed as a tool for detecting the novel mutation in one prematurely born Vietnam infant with HI phenotype. And after that, the mutation was confirmed by the Sanger sequencing method in the patient and the members of his family. In this case, one novel mutation c.6353C > G (p.S2118X, Hom) in the ABCA12 gene, was detected in the patient. The mutation has not been reported in any HI patients previously. This mutation was also found in a heterozygous state in the members of the patient's family, including his parents, an older brother, and an older sister who are no symptoms. Conclusions: In this study, we identified a novel mutation in a Vietnamese patient with HI by whole exome sequencing. The results for the patient and the members of his family will be helpful in understanding the etiology of the disease, diagnosing carriers, assisting in genetic counseling, and emphasizing the need for DNA-based prenatal screening for families with a history of the disease.

Mutational Spectrum of the ABCA12 Gene and Genotype-Phenotype Correlation in a Cohort of 64 Patients with Autosomal Recessive Congenital Ichthyosis.

Autosomal recessive congenital ichthyosis (ARCI) is a non-syndromic congenital disorder of cornification characterized by abnormal scaling of the skin. The three major phenotypes are lamellar ichthyosis, congenital ichthyosiform erythroderma, and harlequin ichthyosis. ARCI is caused by biallelic mutations in ABCA12, ALOX12B, ALOXE3, CERS3, CYP4F22, NIPAL4, PNPLA1, SDR9C7, SULT2B1, and TGM1. The most severe form of ARCI, harlequin ichthyosis, is caused by mutations in ABCA12. Mutations in this gene can also lead to congenital ichthyosiform erythroderma or lamellar ichthyosis. We present a large cohort of 64 patients affected with ARCI carrying biallelic mutations in ABCA12. Our study comprises 34 novel mutations in ABCA12, expanding the mutational spectrum of ABCA12-associated ARCI up to 217 mutations. Within these we found the possible mutational hotspots c.4541G>A, p.(Arg1514His) and c.4139A>G, p.(Asn1380Ser). A correlation of the phenotype with the effect of the genetic mutation on protein function is demonstrated. Loss-of-function mutations on both alleles generally result in harlequin ichthyosis, whereas biallelic missense mutations mainly lead to CIE or LI.

A fatal case of Harlequin ichthyosis: Experience from low-resource setting.

Harlequin ichthyosis is a severe and fatal presentation of ichthyosis with an autosomal recessive inheritance. Infants with Harlequin ichthyosis have a high mortality rate, and a dismal prognosis; therefore the majority of neonates die shortly after birth from infection, heat loss, dehydration, electrolytic imbalances, or respiratory distress. The aim of this case report was to present a fatal case of Harlequin ichthyosis with no family history of any inherited skin disorder. A 3-day-old baby was presented to the emergency room with congenital abnormalities at birth, fissured hyperkeratotic skin, and thick yellow plates of scales. The parents had no history of consanguineous marriage, no relevant past medical history, and no family history of the same condition. The patient was unwell, pulse 162 times/minute, respiratory rate 48 times/minute, and axillary temperature 36.9oC. APGAR score was 8 in the 1st minute and 9 in the 5th minute. Based on the typical clinical appearance, the patient was diagnosed with Harlequin ichthyosis. Due to a lack of facility, a mutation analysis was not carried out. The patient was then transferred to the neonatal intensive care unit (NICU) and treated in a humidified incubator and medicated with intravenous antibiotics (ampicillin sulbactam 125 mg/12 hour and gentamicin 13 mg/24 hour), topically fusidic acid and mild emollients. A central venous catheter was used for intravenous access. The poor prognosis resulted in the patient dying at the age of 5-day-old. This case highlights that prenatal diagnosis is critical for early detection and disease prevention. Mutation screening for the ABCA12 gene is suggested for consanguinity marriages and with a history of ichthyosis.

Harlequin ichthyosis: A case report and literature review.

Harlequin ichthyosis is a rare autosomal recessive disorder occurring in 1: 3,000,000 birth characterized by thick keratin skin with a scaly appearance. Preterm deliveries, early, and consanguinity of marriage are some risk factors. Antenatal checkup of DNA for ABCA12 mutation helps in diagnosis but ultrasonography in places was not available.

Harlequin ichthyosis newborn: A case report.

Harlequin ichthyosis is a rare and severe genetic skin disorder that occurs within the developing foetus. Harlequin ichthyosis is the most severe and devastating form of autosomal recessive congenital ichthyoses. It is caused by mutations in the lipid transporter adenosine triphosphate binding cassette A 12. Here, we reported a case of harlequin ichthyosis with no family history. No abnormalities were detected in prenatal sonography. A 24-year-old pregnant woman with premature rupture of membrane and labour pain was referred to a hospital in Shoushtar city, Iran. The mother delivered a male baby with harlequin ichthyosis. The infant baby died on the 5th day. Harlequin ichthyosis is associated with adenosine triphosphate binding cassette A 12 gene mutation; therefore, genetic screening and counselling for susceptible parents should be taken into account. Prenatal diagnosis of harlequin ichthyosis principally via sonographic techniques is important in managing the disorder.

Harlequin ichthyosis: A case image from Syria.

Harlequin ichthyosis is a rare autosomal recessive congenital ichthyosis with a distinct phenotypic appearance. It associated with a high mortality rate and affects both sexes equally. We report a harlequin fetus with a history of scalp psoriasis in his mother. The neonate was born to consanguineous parents who had a previous female baby that was diagnosed with harlequin ichthyosis.

Management of Harlequin Ichthyosis: A Brief Review of the Recent Literature.

Harlequin ichthyosis (HI) is a life-threatening genetic disorder that largely affects the skin of infants. HI is the most severe form of the autosomal recessive disorder known as ichthyosis. It is caused by mutations in the A12 cassette (lipid-transporter adenosine triphosphate-binding cassette A12). Neonates affected by this disease are born with specific morphological characteristics, the most prominent of which is the appearance of platelet keratotic scales separated by erythematous fissures. The facial features include eclabium, ectropion, a distinct flattened nose, and dysplastic ears. A common finding among those with HI is impaired skin barrier function. The purpose of the present narrative review is to assess the most recent literature regarding the management of HI. Emphasis is given to surgical management and consultation, to the indications for timing and surgical intervention, to the risks that are presented with surgery, and to the details of the surgical procedure itself. Management of HI requires a multidisciplinary team of experts, and specific guidelines are needed in order for the risks to be minimized and viability to be increased.

Harlequin fetus: A case report.

Harlequin ichthyosis (HI) is the most severe type of congenital ichthyosis. It is extremely rare with very few cases reported in India. It is inherited in an autosomal recessive fashion. The importance of antenatal diagnosis by ultrasonography, DNA-based molecular studies on chorionic villus sampling, and amniocentesis has been emphasized. We report a new case of HI in an infant, diagnosed postnatally by correlation of clinical and histopathological features on skin biopsy. The infant succumbed on the second day of birth despite intensive supportive care. A short review of the literature regarding the condition is also presented.

Juvenile idiopathic arthritis in Harlequin ichthyosis, a rare combination or the clinical spectrum of the disease? Report of a child treated with etanercept and review of the literature.

BACKGROUND: Harlequin ichthyosis (HI) is the most severe phenotype of autosomal recessive congenital ichthyosis. Juvenile Idiopathic Arthritis (JIA) represents a heterogenous group of disorders all sharing the clinical manifestation of chronic arthritis. Association of HI and chronic arthritis has been reported in few cases. CASE PRESENTATION: We report the case of a child with HI who developed a severe form of chronic polyarthritis during the first years of life, treated with repeated multiple joint injections, methotrexate and etanercept with good response and without any adverse events. CONCLUSION: The reported case and the literature review highlighted the presence of a peculiar severe seronegative polyarthritis with early onset in a series of patients with HI, suggesting that polyarthritis may be a specific manifestation of HI, rather than a rare combination of two separate conditions.

Ichthyosis: case report in a Colombian man with genetic alterations in ABCA12 and HRNR genes.

BACKGROUND: Ichthyosis is a heterogeneous group of diseases caused by genetic disorders related to skin formation. They are characterized by generalized dry skin, scaling, hyperkeratosis and frequently associated with erythroderma. Among its different types, harlequin ichthyosis (HI) stands out due to its severity. HI is caused by mutations in the ABCA12 gene, which encodes essential proteins in epidermal lipid transport, and it helps maintain the homeostasis of the stratum corneum of the epidermis. However, due to the wide spectrum of genetic alterations that can cause ichthyosis, holistic medical care, and genetic studies are required to improve the diagnosis and outcomes of these diseases. CASE PRESENTATION: Here, we presented the case of a 19 years old male patient who was a premature infant and exhibited clinical features consistent with HI, including bright yellow hyperkeratotic plates with erythematous fissures that covered his entire body like a collodion baby. Currently, he exhibited erythroderma, photosensitivity, ectropion, auricular pavilion alterations, and musculoskeletal disorders, such as equinovarus feet, fingers, hands, and hypoplastic feet with contractures in flexion and marked difficulty in fine motor skills. In addition, he presented dyschromatopsia, Achilles reflex hyporeflexia, slight speech, dental alteration and deficient cognitive performance. After the genetic sequencing, variants were found in ABCA12 and HRNR which are related to several skin diseases, including ichthyosis. CONCLUSIONS: Although in clinical practice, ichthyosis is a common entity, a severe type of ichthyosis is presented, highlighting the importance of appropriate genetic diagnosis, given the broad spectrum of genetic alterations with similar phenotypic and clinical characteristics. These pathologies must be known to guarantee initial support measures to prevent complications and offer multidisciplinary management to those patients.

Guards! Guards! How innate lymphoid cells ensure local law and order.

This special issue of the Biomedical Journal is dedicated to the latest official recruits in the field of immunology: innate lymphoid cells, the tissue-resident sentinels and first responders to damage or invasion. Subsequently, we consider extracellular vesicle release during bacterial infection, how immunomodulation can avoid compromising Mycobacterium tuberculosis clearance, and how innate immunity jeopardises the organism during rheumatoid arthritis. Moreover, we ponder over the predictive value of cardiac troponin in influenza, the virtues of cashew nuts and bilirubin, as well as holes in the heart. Finally, we learn that mandibular movement during swallowing increases with the vertical dimension of occlusion, and that early controlled relaxation incisions restore the blood supply to the extremities in harlequin ichthyosis neonates.

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.

Early escharotomy-like procedure for the prevention of extremity autoamputation in harlequin ichthyosis.

Harlequin ichthyosis is a rare congenital disorder, which causes restrictive circumferential encasement of the trunk and limbs. Patients usually develop compartment syndrome and sequential cyanosis of limbs and digits, leading to autoamputation. We report a case of harlequin ichthyosis in which all digits were preserved with an early escharotomy-like procedure. A 33-6/7-week-old preterm girl presented with whole body hyperkeratosis, constrictive bands on neck, chest, abdominal, limbs, and developed compartment syndrome. On the second day after birth, distal digits progressive swelling and ischemic change occurred. An escharotomy-like procedure was performed on all 4 extremities to the distal digits. All distal phalanges and nail plate were well preserved at 5-month follow-up. We concluded that for prevention of digits autoamputation in harlequin ichthyosis, early detection of compartment syndrome is necessary and an escharotomy-like procedure should be performed as soon as possible when ischemia occurs.

Prenatal diagnosis of a rare variant of harlequin ichthyosis with literature review.

BACKGROUND: Harlequin ichthyosis (HI) is a rare and severe genetic skin disorder that occurs within the developing foetus. Due to the extremely poor prognosis, prenatal diagnosis becomes very important, especially for foetuses with no family history. There are few reports on prenatal diagnosis in PubMed. CASE PRESENTATION: We report two cases of HI with no family history who were diagnosed by prenatal ultrasound. We searched for reports on the prenatal ultrasonic diagnosis of HI over nearly two decades and summarized the sonographic features of HI, the reasons for missed diagnoses and matters needing attention. A total of 10 articles of congenital harlequin ichthyosis diagnosed by prenatal ultrasound in PubMed were retrieved. There have been even fewer reports of late-trimester disease with no family history. Combining the two cases we reported with the literature review, we summarize the ultrasonic image characteristics of HI. CONCLUSION: HI can be easily detected by 2D ultrasound combined with 3D, but attention should be paid to a systematic examination in the third trimester of pregnancy according to the clinical characteristics of the disease.