Unbound Corneocyte Lipid Envelopes in 12R-Lipoxygenase Deficiency Support a Specific Role in Lipid-Protein Cross-Linking.

Loss-of-function mutations in arachidonate lipoxygenase 12B (ALOX12B) are an important cause of autosomal recessive congenital ichthyosis (ARCI). 12R-lipoxygenase (12R-LOX), the protein product of ALOX12B, has been proposed to covalently bind the corneocyte lipid envelope (CLE) to the proteinaceous corneocyte envelope, thereby providing a scaffold for the assembly of barrier-providing, mature lipid lamellae. To test this hypothesis, an in-depth ultrastructural examination of CLEs was performed in ALOX12B-/- human and Alox12b-/- mouse epidermis, extracting samples with pyridine to distinguish covalently attached CLEs from unbound (ie, noncovalently bound) CLEs. ALOX12B--/- stratum corneum contained abundant pyridine-extractable (ie, unbound) CLEs, compared with normal stratum corneum. These unbound CLEs were associated with defective post-secretory lipid processing, and were specific to 12R-LOX deficiency, because they were not observed with deficiency of the related ARCI-associated proteins, patatin-like phospholipase 1 (Pnpla1) or abhydrolase domain containing 5 (Abhd5). These results suggest that 12R-LOX contributes specifically to CLE-corneocyte envelope cross-linking, which appears to be a prerequisite for post-secretory lipid processing, and provide insights into the pathogenesis of 12R-LOX deficiency in this subtype of ARCI, as well as other conditions that display a defective CLE.

Antenatal Findings of Keratitis-Ichthyosis-Deafness Syndrome.

BACKGROUND: Keratitis-ichthyosis-deafness (KID) syndrome is a congenital ectodermal disorder characterized by keratitis, ichthyosis, and deafness. This syndrome affects multiple systems and can be fatal. CASE: A 34-year-old G2, P1 woman was admitted to the Ege University School of Medicine in Izmir, Turkey because of a rapid increase in abdominal circumference at 32 weeks gestation. Fetal anatomic screening revealed complete chorioamniotic separation, hypoplasia of the cerebellar vermis, and dysmorphic facial findings such as frontal bulging. After the delivery, the baby's whole body had granular thickened skin. Bilateral dry eye, corneal edema, and bilateral retinopathy of prematurity were diagnosed. CONCLUSION: This case report highlights the importance of prenatal diagnosis through ultrasonography and magnetic resonance imaging. This is the first case report that has antenatal ultrasonographic features in the literature.

Chromosomal inversions as a hidden disease-modifying factor for somatic recombination phenotypes.

Heterozygous chromosomal inversions suppress recombination. Therefore, they may potentially influence recombination-associated phenotypes of human diseases, but no studies have verified this hypothesis. Here, we describe a 35-year-old man with severe congenital ichthyosis. Mutation analysis revealed a heterozygous splice-site mutation, c.1374-2A>G (p.Ser458Argfs*120), in KRT10 on 17q21.2. This mutation was previously reported in patients with ichthyosis with confetti type I (IWC-I), a prominent skin disease characterized by the frequent occurrence of recombination-induced reversion of pathogenic mutations. Intriguingly, the number of revertant skin areas in this patient is considerably reduced compared with typical IWC-I cases. G-banded karyotyping revealed that the patient harbors a heterozygous nonpathogenic inversion, inv(17)(p13q12), whose long-arm breakpoint was subsequently refined to chromosomal positions (chr17: 36,544,407-36,639,830) via FISH. Collectively, the only chance of revertant mosaicism through somatic recombination appears to involve recombination between the KRT10 mutation and the inversion breakpoint. Indeed, in the examined revertant spot, the KRT10 mutation was diminished by somatic recombination starting from chromosomal positions (chr17: 36,915,505-37,060,285) on 17q12. This study provides the first evidence to our knowledge implicating chromosomal inversions as a potential modifier of clinical phenotypes. Furthermore, the reduced occurrence of revertant spots in the recombination-suppressed patient suggests that somatic recombination is the main mechanism of revertant mosaicism in IWC-I.

Dominant ELOVL1 mutation causes neurological disorder with ichthyotic keratoderma, spasticity, hypomyelination and dysmorphic features.

BACKGROUND: Ichthyosis and neurological involvement occur in relatively few known Mendelian disorders caused by mutations in genes relevant both for epidermis and neural function. OBJECTIVES: To identify the cause of a similar phenotype of ichthyotic keratoderma, spasticity, mild hypomyelination (on MRI) and dysmorphic features (IKSHD) observed in two unrelated paediatric probands without family history of disease. METHODS: Whole exome sequencing was performed in both patients. The functional effect of prioritised variant in ELOVL1 (very-long-chain fatty acids (VLCFAs) elongase) was analysed by VLCFA profiling by gas chromatography-mass spectrometry in stably transfected HEK2932 cells and in cultured patient's fibroblasts. RESULTS: Probands shared novel heterozygous ELOVL1 p.Ser165Phe mutation (de novo in one family, while in the other family, father could not be tested). In transfected cells p.Ser165Phe: (1) reduced levels of FAs C24:0-C28:0 and C26:1 with the most pronounced effect for C26:0 (P=7.8×10-6 vs HEK293 cells with wild type (wt) construct, no difference vs naïve HEK293) and (2) increased levels of C20:0 and C22:0 (P=6.3×10-7, P=1.2×10-5, for C20:0 and C22:0, respectively, comparison vs HEK293 cells with wt construct; P=2.2×10-7, P=1.9×10-4, respectively, comparison vs naïve HEK293). In skin fibroblasts, there was decrease of C26:1 (P=0.014), C28:0 (P=0.001) and increase of C20:0 (P=0.033) in the patient versus controls. There was a strong correlation (r=0.92, P=0.008) between the FAs profile of patient's fibroblasts and that of p.Ser165Phe transfected HEK293 cells. Serum levels of C20:0-C26:0 FAs were normal, but the C24:0/C22:0 ratio was decreased. CONCLUSION: The ELOVL1 p.Ser165Phe mutation is a likely cause of IKSHD.

NEW APPROACHES IN THE DIAGNOSTIC OF ICHTHYOSIS DISORDERS.

The aim of this study was to study the macroscopic changes in the skin of patients with various forms of ichthyosis to improve and optimize treatment. A comprehensive examination of 12 patients with ichthyosis under the supervision of a dermatovenereologist was conducted at VOKSHVD. For the diagnosis of macroscopic skin changes, the dermatoscopy was performed by the HEINE DELTA 20 ® (Germany) apparatus, the results were recorded with a Canon 550D camera (Japan) at 1:35 or 1:30, with a sensitivity of IZO 200 using an adapter included with the dermatoscope. All affected skin were examined, which were compared with unharmed ones. The task was performed using the algorithm developed by us for dermatoscopic assessment of the severity of ichthyosis. The presence of typical dermatoscopic signs in examined patients with ichthyosis, which is manifested by the smoothness of the skin pattern, the presence of a pseudo-pigmental mesh, formed by keratin of scales in the form of lines, mesh and loop structures resembling cerebriform components, are established. The algorithm of estimation of expressiveness of dermatoscopic features for patients with light and severe clinical course of ichthyosis is proposed. Also, specific dermatological signs were observed in the mild clinical course of ichthyosis, in particular the phenomenon of «sparkling champagne¼, and in severe clinical course, the «melting ice¼ phenomal. The use of the dermatoscopic method makes it possible to objectively evaluate the severity of the ichthyosis and apply a differentiated approach to choosing the most effective treatment schemes.

Infantile Serine Biosynthesis Defect Due to Phosphoglycerate Dehydrogenase Deficiency: Variability in Phenotype and Treatment Response, Novel Mutations, and Diagnostic Challenges.

Serine biosynthesis defects can present in a broad phenotypic spectrum ranging from Neu-Laxova syndrome, a lethal disease with multiple congenital anomalies at the severe end, to an infantile disease with severe psychomotor retardation and seizures as an intermediate phenotype, to a childhood disease with intellectual disability at the mild end. In this report we present 6 individuals from 3 families with infantile phosphoglycerate dehydrogenase (PGDH) deficiency who presented with psychomotor delay, growth failure, microcephaly, and spasticity. The phenotype was variable with absence of seizures in 2 sisters in family 1 and 1 infant in family 2 and seizures with pronounced happy affect in 3 sisters in family 3. The initiation of serine treatment had pronounced effect on seizures and spasticity in the sisters in family 3, but minimal developmental effects on the children in families 1 and 2. With such phenotypic variability, the diagnosis of PGDH deficiency can be challenging.

[Neu-Laxova syndrome: Three case reports and a review of the literature]. / Syndrome de Neu-Laxova : rapport de trois cas et revue de la littérature.

INTRODUCTION: The Neu-Laxova syndrome (NLS) is a rare autosomal recessive and early lethal disorder. It is characterized by severe intra-uterine growth retardation, abnormal facial features, ichthyotic skin lesions and severe central nervous system malformations, especially microlissencephaly. Others characteristic features associated with fetal hypokinesia sequence, including arthrogryposis, subcutaneous edema and pulmonary hypoplasia, are frequently reported in NLS. PATIENTS AND METHODS: The clinicopathological characteristics of NLS are described in three cases with striking prenatal diagnostic findings and detailed post-mortem examinations. A review of the literature is undertaken with a focus on molecular basis. RESULTS: We present three new patients with NLS: one stillbirth male and two female newborns, delivered at 29, 35 and 40 weeks of gestational age, respectively. Characteristic ultrasound findings included hydramnios, severe intra-uterine growth restriction, craniofacial and cental nervous system anomalies. The cytogenetic study, performed in one case, was normal. The post-mortem examination revealed characteristic abnormalities in all three cases, that allowed to make a prompt diagnosis of the NLS. Data from these patients suggest that the NLS represents a heterogeneous phenotype. This feature has been highlighted in the literature. CONCLUSION: The SNL is a lethal developmental disorder characterized by phenotypic heterogeneity with striking neurological defects. It is underpinned by genetic heterogeneity. It can be caused by mutations in all three genes involved in de novo L-serine biosynthesis: PHGDH, PSAT1 and PSPH. Hence, the NLS constitutes the most severe end of already known human disease, i.e. serine-deficiency disorder.

Dermoscopy of Grover's disease: Variability according to histological subtype.

Distinguishing Grover's disease from other papular dermatoses is often a troublesome task. According to two relatively recent case reports, dermoscopy may be useful in assisting the diagnosis of such a disorder by showing a peculiar pattern. The aim of this study was to evaluate the dermoscopic features of Grover's disease in a larger series of patients and correlate dermoscopy with histopathological findings. Seven patients with histopathologically confirmed Grover's disease were included in the study, with three of them displaying a Darier-like histology and the remaining four cases having a spongiotic histological pattern. The results of our study suggest that Grover's disease may display different features according to the histological subtype, with a central star-shaped/branched polygonal/roundish-oval brownish area surrounded by a whitish halo being characteristic of the Darier-like histological subtype and whitish scales over a reddish-yellowish background being characteristic of the spongiotic histological subtype.

Grover disease (transient acantholytic dermatosis) in acute myeloid leukemia on FDG PET/CT.

A 48-year-old man with a newly diagnosed acute myeloid leukemia developed purpuric rash on day 6 after chemotherapy. Skin biopsy on day 8 demonstrated Grover disease. Triamcinolone treatment started on day 10 with subjective improvement on day 15. Initial FDG PET/CT on day 12 demonstrated rarely seen diffuse skin uptake that was interpreted as technical artifact and repeated on day 16. Accurately reviewing both PET and CT imaging would prevent confusion between diffuse cutaneous hypermetabolic activity and a technical artifact. Grover disease usually affects the trunk and may be related to the elimination of chemotherapy agents by sweating.

Ichthyosis prematurity syndrome with separation of fetal membranes and neonatal asphyxia.

Ichthyosis prematurity syndrome (IPS) is a rare inherited skin disorder. Children are born prematurely with thick skin and have been found to develop neonatal asphyxia due to occlusions in the bronchial tree from debris in the amniotic fluid. At 31 weeks of gestation, separation of amniotic and chorionic membranes was identified as well as polyhydramnion. The child was born 2 weeks later, with thickened skin with a granular appearance and required immediate ventilation and intensive care. At 2 years of age, the patient has developed an atopic skin condition with severe itching, recurrent skin infections, food intolerance and periods of wheezing. Prenatal observation of separation of foetal membranes or dense amniotic fluid may be signs of IPS and severe complication immediately after birth.

Prenatal sonographic assessment and perinatal course of ichthyosis prematurity syndrome.

All cases of ichthyosis prematurity syndrome (IPS), registered at the National Center for Fetal Medicine in Trondheim, Norway between 1987 and 2010 were identified and the findings analyzed. Five fetuses with IPS were identified between 1988 and 2000. All five developed polyhydramnios between 28 and 31 weeks. The fetal stomach appeared to be empty in four cases, and was not described in one case. The fetal skin was described as 'uneven' at ultrasound examination in two cases. Separation of chorionic and amniotic membranes with a peculiar appearance of echo-free fluid in the chorionic cavity and echogenic sediment in the amniotic cavity were observed between 28 + 5 and 32 + 3 weeks in all cases. All fetuses were delivered prematurely between 30 and 34 weeks. All neonates had difficulties in breathing, two developed aspiration pneumonia, and one had bilateral pneumothorax after intubation and died at 6 months because of pulmonary and cardiac sequelae. Prenatal sonographic signs of IPS are separation of the membranes, echogenic amniotic fluid and echo-free chorionic fluid occurring between 28 and 32 weeks' gestation. Delivery occurs at 30-34 weeks and, as there is a high risk of asphyxia, an experienced neonatal intensive care unit team should be present at delivery.

Neu-Laxova syndrome: a prenatal diagnosis.

Neu-Laxova syndrome is a rare autosomal recessive congenital disorder. Prenatal diagnosis is possible via second trimester ultrasonography. Characteristic ultrasound findings include hydramnios, severe intrauterine growth restriction, craniofacial and CNS anomalies, limb contractures, skin lymphedema, skin restrictions, and akinesia. Fewer than 70 cases have been reported, and no survival beyond six months of age is known with most neonatal deaths occurring within the first few days of life. Overall, this is a lethal condition after birth secondary to severe lung hypoplasia and brain anomalies. Herein we report a recent case from our institution with prenatal diagnosis.

A spectrum of phenotypical expression OF Neu-Laxova syndrome: Three case reports and a review of the literature.

Neu-Laxova syndrome is a rare autosomal recessive disorder characterized by severe intra-uterine growth restriction, extreme microcephaly, marked edema with skin restriction, ichthyosis, craniofacial anomalies, limb deformities, and a spectrum of central nervous system malformations. Less than 70 cases have been described since the first report in 1971. To this day the etiology and genetic basis remains unknown. Consanguinity has been reported. Some authors have postulated the syndrome to be a form of neuro-ectodermal dysplasia, while others suggest that it is a malformation syndrome secondary to severe skin restriction. Although the outcome of this syndrome is lethal, a single case of longer survival (6 months) has been reported. The majority of cases are stillborn or die shortly after birth. Thus, it is clear that Neu-Laxova exhibits a spectrum of disease, with varying degrees of phenotypic expression. We are presenting three new cases of Neu-Laxova syndrome; two were stillbirths and one lived for eleven weeks. Our microscopic and post-mortem findings in these three cases display the vast spectrum of this rare syndrome.

Prenatal sonographic features of Harlequin ichthyosis.

Harlequin ichthyosis (HI) is a severe and usually fatal congenital keratinization disorder with autosomal recessive inheritance. For over a decade, prenatal diagnosis of HI relied on fetoscopic or sonographically guided skin biopsies, and, therefore, was limited to previously affected families. Only a few cases of prenatal sonographic diagnosis have been published and the sonographic findings are variable. We report a case of HI, in which the typical features were detected during fetal life but the condition remained undiagnosed at 35 weeks' gestational age in this pregnancy complicated by premature rupture of membranes, oligohydramnios and intrauterine growth retardation. The documented prenatal findings were a flat profile with absent nose; a large mouth, widely gaping open; dysplastic ears; abnormal fixed position of the hands; and edema of thighs and feet; and intrauterine growth retardation. Following elective cesarean section the infant died of septicemia 12 days post-partum despite etretinate and antibiotic treatment. The sonographic features of HI are discussed together with those previously reported and an attempt is made to delineate sonographic markers of this rare disorder.

Intra-amniotic debris identified at ultrasound scanning: a feature of congenital ichthyosis.

A case is described in which intra-amniotic debris was identified during an ultrasound scan in a woman with polyhydramnios at 33 weeks' gestation. At delivery the neonate was found to have severe ichthyosis involving the whole of her head, trunk and limbs, with large plaques of hyperkeratotic skin on the palms of her hands and the soles of her feet. The finding of excessive debris in association with polyhydramnios should raise the possibility of an exfoliative skin disorder.