Progressive hyperpigmentation in a Taiwanese child due to an inborn error of vitamin B12 metabolism (cblJ).

The physiology of human skin pigmentation is varied and complex, with an extensive melanogenic paracrine network involving mesenchymal and epithelial cells, contributing to the regulation of melanocyte survival and proliferation and melanogenesis. Mutations in several genes, involving predominantly the KIT ligand/c-Kit and Ras/mitogen-activated protein kinase signalling pathways, have been implicated in a spectrum of diseases in which there is hyperpigmentation, hypopigmentation or both. Here, we report on a 12-year-old girl from Taiwan with a 6-year history of diffuse progressive skin hyperpigmentation resulting from a different aetiology: an inborn metabolic disorder of vitamin B12 (cobalamin), designated cblJ. Using whole-exome sequencing we identified a homozygous mutation in ABCD4 (c.423C>G; p.Asn141Lys), which encodes an ATP-binding cassette transporter with a role in the intracellular processing of cobalamin. The patient had biochemical and haematological evidence of cobalamin deficiency but no other clinical abnormalities apart from a slight lightening of her previously black hair. Of note, she had no neurological symptoms or signs. Treatment with oral cobalamin (3 mg daily) led to metabolic correction and some reduction in the skin hyperpigmentation at the 3-month follow-up. This case demonstrates that defects or deficiencies of cobalamin should be remembered in the differential diagnosis of diffuse hyperpigmentary skin disorders.

LRIG1 modulates aggressiveness of head and neck cancers by regulating EGFR-MAPK-SPHK1 signaling and extracellular matrix remodeling.

EGFR overexpression and chromosome 3p deletion are two frequent events in head and neck cancers. We previously mapped the smallest region of recurrent copy-number loss at 3p12.2-p14.1. LRIG1, a negative regulator of EGFR, was found at 3p14, and its copy-number loss correlated with poor clinical outcome. Inducible expression of LRIG1 in head and neck cancer TW01 cells, a line with low LRIG1 levels, suppressed cell proliferation in vitro and tumor growth in vivo. Gene expression profiling, quantitative RT-PCR, chromatin immunoprecipitation, and western blot analysis demonstrated that LRIG1 modulated extracellular matrix (ECM) remodeling and EGFR-MAPK-SPHK1 transduction pathway by suppressing expression of EGFR ligands/activators, MMPs and SPHK1. In addition, LRIG1 induction triggered cell morphology changes and integrin inactivation, which coupled with reduced SNAI2 expression. By contrast, knockdown of endogenous LRIG1 in TW06 cells, a line with normal LRIG1 levels, significantly enhanced cell proliferation, migration and invasiveness. Such tumor-promoting effects could be abolished by specific MAPK or SPHK1 inhibitors. Our data suggest LRIG1 as a tumor suppressor for head and neck cancers; LRIG1 downregulation in cancer cells enhances EGFR-MAPK-SPHK1 signaling and ECM remodeling activity, leading to malignant phenotypes of head and neck cancers.

Collodion baby and loricrin keratoderma: a case report and mutation analysis.

Hereditary palmoplantar keratodermas (PPK) comprise a clinically and genetically heterogeneous group of genodermatoses, which share the characteristic of impaired epidermal differentiation, resulting in prominent palmoplantar hyperkeratosis. Molecular genetic analyses have helped characterize the underlying genetic defects in an increasing number of hereditary PPKs over the past two decades, and thus a pathophysiological classificaiton seems more reasonable. Today PPK can be classified based on defects in keratins, loricrin, desmosomes, connexins and cathepsins. In this report, we describe a 22-year-old man who had been born a collodion baby, and later developed diffuse PPK with pseudoainhum and generalized ichthyosis. His mother and grandmother had similar characteristics. Direct sequencing of genomic DNA identified a frameshift insertion mutation (730insG) in the loricrin gene. This family had the typical presentation of loricrin keratoderma. It also indicates that collodion baby may be the first presentation in patients with loricrin keratoderma.

A retrospective study of pulmonary infarction in patients with systemic lupus erythematosus from southern Taiwan.

Since large-scale reports of pulmonary infarction in systemic lupus erythematosus (SLE) are limited, a retrospective study was performed for this manifestation in 773 hospitalized patients in southern Taiwan from 1999 to 2009. Pulmonary infarction was defined as the presence of pulmonary embolism, persistent pulmonary infiltrates, and characteristic clinical symptoms. Demographic, clinical, laboratory, and radiological images data were analyzed. There were 12 patients with pulmonary embolism and 9 of them had antiphospholipid syndrome (APS). Six patients (19 to 53 years, average 38.2 ± 12.6) with 9 episodes of lung infarction were identified. All cases were APS and four episodes had coincidental venous thromboembolism. There were four episodes of bilateral infarction and seven episodes of larger central pulmonary artery embolism. Heparin therapy was routinely prescribed and thrombolytic agents were added in two episodes. Successful recovery was noted in all patients. In conclusion, there was a 0.8% incidence of pulmonary infarction in patients with SLE, all with the risk factor of APS. Differentiation between pulmonary infarction and pneumonia in lupus patients should be made; they have similar chest radiography with lung consolidation but require a different clinical approach in management. Although this report is a retrospective study with relatively small numbers of lupus patients with lung infarcts, our observation might provide beneficial information on the clinical features and radiological presentations during the disease evolution of pulmonary infarction in SLE with APS.

Mutations in TRPS1 gene in trichorhinophalangeal syndrome type I in Asian patients.

The trichorhinophalangeal syndromes (TRPSs) are rare hereditary diseases with mainly autosomal dominant inheritance. Three different forms sharing similar clinical features with heterogeneous mutations have been identified: type I (TRPS I), type II (TRPS II) and type III (TRPS III). These syndromes have characteristic facial abnormalities such as sparse and slow-growing scalp hair, laterally sparse eyebrows, bulbous pear-shaped nose, elongated and flat philtrum, thin upper lip, and protruding ears. Various skeletal abnormalities are also frequently noted: short stature, shortening of the phalanges and metacarpals, cone-shaped epiphyses and Perthes-like change of the hips.(1-4) The TRPS1 gene was first identified in 2000 and mapped to 8q24.1.(1) More than 50 mutations have been found in the gene to date. We here report mutation analysis of eight patients with the typical phenotype of TRPS I, revealing five novel mutations.

Novel exon nucleotide substitution at the splice junction causes a neonatal Marfan syndrome.

The fibrillin-1 gene (FBN1) mutations are associated with a broad spectrum of disorders including Marfan syndrome (MFS) and show great clinical heterogeneity. An underrepresentation for mutations leading to premature termination codon (PTC) in FBN1 exons 24-32 was found in neonatal or severe MFS but the underlying cause was unclear. This study thoroughly examined two FBN1 mutations on exons 24-32 region to illustrate the molecular mechanisms underlying these FBN1 mutations on MFS etiology. Two nucleotide substitutions, c.3208G> C, the last nucleotide of exon 26, and c.3209A>G, the first nucleotide of exon 27, affecting the same amino acid, p.D1070H and p.D1070G, respectively, gave very different phenotypes. We demonstrate that c.3208G>C generates two alternatively spliced transcripts, while c.3209A>G does not affect the splicing. We further demonstrate that the aberrantly spliced transcripts do not go through nonsense-mediated decay, but rather produce unstable, premature protein peptides that are degraded by endoplasmic reticulum associated degradation. The molecular mechanism outlined here defines a model for the pathogenesis of PTC-containing mutation within the exons 24-32 of FBN1 in MFS. Furthermore, our data suggest that PTC mutation within this region may lead to early lethality in neonatal MFS.

Analysis of Taiwanese ichthyosis vulgaris families further demonstrates differences in FLG mutations between European and Asian populations.

BACKGROUND: Mutations in the gene encoding filaggrin (FLG) were identified to underlie ichthyosis vulgaris (IV) and also shown to predispose to atopic eczema. Until now, no FLG mutations have been described in the Taiwanese population. OBJECTIVES: To elucidate filaggrin mutations in the Taiwanese population and further to clarify the population genetics of filaggrin gene mutations in the Asian populations. METHODS: In the present study, 12 individuals from four unrelated Taiwanese IV families were examined for FLG mutations. We carried out comprehensive sequencing of the entire FLG coding region using an overlapping polymerase chain reaction strategy. RESULTS: We identified three FLG mutations in the Taiwanese IV families. One mutation E1795X was a previously unidentified FLG mutation, which might be specific to the Taiwanese. Interestingly, another FLG mutation 3321delA is prevalent in the Japanese population and the other mutation Q2417X was found in the Singaporean Chinese population. No FLG mutation identified in the white European population was found in the Taiwanese population. CONCLUSIONS: The present findings suggest that the Taiwanese population, as an East Asian group, share FLG mutations with both the Japanese and the Singaporean Chinese population. In addition, these results exemplify differences in the population genetics of filaggrin between Europe and Asia.

A novel splicing mutation of the CYLD gene in a Taiwanese family with multiple familial trichoepithelioma.

Multiple familial trichoepithelioma (MFT) is an autosomal dominant disease characterized by numerous skin-coloured papules on the central face. Mutations in the CYLD gene, which is also the gene responsible for familial cylindromatosis, have been reported recently. Recent studies indicate that CYLD is a tumour-suppressor gene. The CYLD protein is a negative regulator of the activation of transcription factor nuclear factor-kappaB, and loss of CYLD contributes to oncogenesis. We report a novel splicing mutation (IVS12 + 1 G-->A) in the CYLD gene in a Taiwanese pedigree with MFT, and discuss new developments in treatment options.

Minimally invasive keyhole approach for removal of a migratory balloon complicated by endovascular embolization of a carotid-cavernous fistula.

PURPOSE: This report presents our experience in using a minimally invasive keyhole approach to remove a migratory balloon in the cerebral artery in one patient. CASE REPORT: A 19-year-old male suffered from carotid-cavernous fistula after craniofacial trauma two months previously. The patient received endovascular embolization of a carotid-cavernous fistula with detachable balloons. Unfortunately, migration of one balloon to the right middle cerebral artery (MCA) at the M1-M2 junction was noted after detaching the balloon during this procedure. Volume expansion, anticoagulation therapy and an emergency pterional keyhole approach with removal of the displaced balloon were performed successfully. Transient left hemiparesis due to temporary occlusion of the right middle cerebral artery by the balloon was promptly alleviated. There was no definite neurological sequel after the operation. CONCLUSIONS: Although detachable balloon embolization is the best initial treatment of direct carotid-cavernous fistulas, it is likely to migrate to downstream cerebral arteries. We recommend a minimally invasive pterional keyhole approach as a good alternative for treating such endovascular complications to improve outcome.

Capillary morphogenesis gene-2 mutation in infantile systemic hyalinosis: ultrastructural study and mutation analysis in a Taiwanese infant.

Infantile systemic hyalinosis (ISH) is a very rare infantile stiff-skin syndrome characterized by extensive deposits of hyaline material in various organs, especially the skin and gingiva. Recent studies identified pathogenic mutations in the capillary morphogenesis gene 2 (CMG2) in both ISH and juvenile hyaline fibromatosis (JHF). Capillary morphogenesis protein-2 is an integrin-like cell surface receptor for laminins and type IV collagen, and may play a key role in cell-matrix or cell-cell interactions. We report a case of ISH in a 13-month-old Taiwanese girl who manifested progressive joint contractures, recurrent chest infections, chronic diarrhoea with severe hypoalbuminemia and ascites, gum hypertrophy, and violaceous papules and nodules over the occipital area, neck, lumbosacral and anogenital areas since birth. Skin biopsy revealed a thickened and hyalinized papillary dermis. Electron microscopy showed abundant extracellular fibrillogranular material and active fibroblasts with conspicuous Golgi complex filled with fibrillar material. Mutation analysis identified a homozygous 1073-1074insC mutation of CMG2 which had been reported in four other families and may represent a mutation hot spot.

Netherton syndrome: report of two Taiwanese siblings with staphylococcal scalded skin syndrome and mutation of SPINK5.

Netherton syndrome (NS) is a severe autosomal recessive ichthyosis. It is characterized by congenital ichthyosiform erythroderma, trichorrhexis invaginata, ichthyosis linearis circumflexa, atopic diathesis and frequent bacterial infections. Pathogenic mutations in SPINK5 have recently been identified in NS. SPINK5 encodes lymphoepithelial Kazal-type-related inhibitor (LEKTI), a new type of serine protease inhibitor involved in the regulation of skin barrier formation and immunity. We report two Taiwanese brothers with NS. The patients had typical manifestations of NS with an atopic diathesis and recurrent staphylococcal infections, including staphylococcal scalded skin syndrome (SSSS) since birth. Horny layers were obtained by skin surface biopsy for electron microscopy from lesional skin of both patients and from normal controls. All 33 exons and flanking intron boundaries of SPINK5 were amplified for direct sequencing. The ultrastructure of the stratum corneum (SC) was characterized by premature degradation of corneodesmosomes (CDs) with separation of corneocytes. A homozygous 2260A --> T (K754X) mutation of SPINK5 was found in both patients. Staphylococcal exfoliative toxin A (ETA) is a serine protease capable of cleaving desmoglein 1, an important adhesive molecule of CDs, and can cause separation of the SC, resulting in SSSS. The premature degradation of CDs found in our patients may be attributable to insufficient LEKTI, and possibly also to colonization/infection of ETA-producing Staphylococcus aureus. Mechanisms involved in the pathogenesis of the skin barrier defect in NS are proposed. Further study is needed to prove this hypothesis.

A novel 7-bp deletion mutation in a Taiwanese family with X-linked hypohidrotic ectodermal dysplasia.

Hypohidrotic ectodermal dysplasia (HED) is found worldwide with an estimated incidence of 1 per 100,000 births. X-linked hypohidrotic ectodermal dysplasia (XLHED, OMIM 305100) is the most common form of the ectodermal dysplasias (ED), a rare group of hereditary diseases characterized by abnormal development of eccrine sweat glands, hair, and teeth. Heterozygous carriers of XLHED often manifest minor or moderate degrees of hypotrichosis, hypodontia, and hypohidrosis. ED1, the gene for XLHED encodes ectodysplasin A, which is a new member of the tumour necrosis factor family. The majority of mutations in XLHED are missense mutations, but one-fifth are insertion/deletions. Here we report a novel 7-bp deletion mutation (nt1242-1248) in exon 9 of the ED1 gene that results in a frameshift and premature stop codon (PTC + 38 amino acids). Mutation analysis in families with XLHED allows for genetic counselling, prenatal diagnosis and confirmation of carrier status.