Types of congenital nonsyndromic ichthyoses.

Congenital ichthyoses are a very heterogeneous group of diseases manifested by dry, rough and scaling skin. In all forms of ichthyoses, the skin barrier is damaged to a certain degree. Congenital ichthyoses are caused by various gene mutations. Clinical manifestations of the individual types vary as the patient ages. Currently, the diagnosis of congenital ichthyoses is based on molecular analysis, which also allows a complete genetic counseling and genetic prevention. It is appropriate to refer the patients to specialized medical centers, where the cooperation of a neonatologist, a pediatric dermatologist, a geneticist and other specialists is ensured.

Placental steroid sulphatase deficiency: an approach to antenatal care and delivery.

Placental steroid sulphatase deficiency (SSD) is an X-linked inborn error of metabolism. Congenital X-linked ichthyosis (XLI) is a genetic disorder of keratinisation caused by steroid sulphatase (STS) deficiency, which results in a scaling skin condition in male infants shortly after birth. It may be associated with failed induction of labor and prolonged labor leading to cesarean delivery due to 'cervical dystocia'. We present two cases of congenital ichthyosis. Thorough counselling of women with a previously affected pregnancy during the antenatal period should include discussion about mode of delivery and a critical review of the complexities of prenatal diagnosis in this condition. We propose a clinical management pathway to offer women with a previous pregnancy affected by this rare condition. SIMILAR CASES PUBLISHED: Less than 50 cases reported.

Ichthyosis in the Neonatal Setting.

BACKGROUND: There exists a group of rare, inherited scaly skin disorders, generally termed ichthyosis, that can be evident in the infant at the time of birth. Phenotypes for this disorder span the gamut of severity and may pose complex challenges to the healthcare provider. PURPOSE: This article explores the 3 most common nonsyndromic forms of ichthyosis seen in neonates as follows: X-linked recessive, lamellar, and bullous congenital ichthyosiform erythroderma. Moreover, harlequin ichthyosis, a lamellar subtype, is highlighted for being the most severe, clinically problematic, and often lethal form of the disorder. FINDINGS/RESULTS: A description of each of these types and their incidence is included, followed by an explanation of the genetic mutations causing them. The phenotypes and natural history are reviewed, as is expected management of the disorder throughout the patient's lifetime. IMPLICATIONS FOR PRACTICE: Considerations for the neonatal nurse practitioner charged with caring for these patients, including specific recommendations for care in the clinical setting, are discussed. Additionally, genetic counseling and the risks of reoccurrence are explored. IMPLICATIONS FOR RESEARCH: Given the rare nature of this disorder, further research is warranted so that healthcare providers are prepared to provide optimal care to these fragile patients.

X-linked ichthyosis: an oculocutaneous genodermatosis.

X-linked ichthyosis (XLI) is an X-linked recessive disorder of cutaneous keratinization with possible extracutaneous manifestations. It was first described as a distinct type of ichthyosis in 1965. XLI is caused by a deficiency in steroid sulfatase activity, which results in abnormal desquamation and a retention hyperkeratosis. XLI is usually evident during the first few weeks of life as polygonal, loosely adherent translucent scales in a generalized distribution that desquamate widely. These are quickly replaced by large, dark brown, tightly adherent scales occurring primarily symmetrically on the extensor surfaces and the side of the trunk. In addition, extracutaneous manifestations such as corneal opacities, cryptorchidism, and abnormalities related to contiguous gene syndromes may be observed. Diagnosis of XLI is usually made clinically, as the histopathology is nonspecific, but confirmation may be obtained through either biochemical or genetic analysis. Treatment should focus on cutaneous hydration, lubrication, and keratolysis and includes topical moisturizers and topical retinoids.

Harlequin baby: a case report.

Harlequin fetus is a rare and the most severe form of congenital ichthyosis. Most of the infants die within a few weeks after birth due to sepsis and respiratory difficulties. The case of a female harlequin baby is reported. The baby survived because of good neonatal intensive care, topical emollients and oral etretinate. Now she is over three years old and the skin developed into congenital non-bullous ichthyosiform erythroderma. Unfortunately she had delayed growth and development. This is the first case report of a harlequin fetus in Thailand that had prolonged survival.

Correction of steroid sulfatase deficiency by gene transfer into basal cells of tissue-cultured epidermis from patients with recessive X-linked ichthyosis.

To develop an experimental model for somatic gene therapy we have tried to correct the steroid sulfatase (STS) deficiency in tissue-cultured primary epidermal keratinocytes from patients suffering from recessive X-linked ichthyosis. An efficient Epstein-Barr virus-based vector was constructed, in which full-length steroid sulfatase cDNA is located between an SV40 early promotor and processing signals. After STS gene transfer into cultured basal cells from ichthyotic skin, the cells produce large amounts of enzymatically active steroid sulfatase protein. The subpopulation of transfected cells can be made to produce approximately 100 times more STS activity than normal keratinocytes. Keratinocytes from patients suffering from recessive X-linked ichthyosis display an abnormal phenotype when developing a multilayered tissue in culture: Initially an extensive burst of keratinization is observed, followed by rapid, premature shedding and degradation of most suprabasal cell layers, leaving a culture with hyperproliferative relatively immature keratinocytes. Transfection of these immature ichthyotic cells with the functional STS construct led to an increase in the amount of retained cell material in the culture medium, indicating an increased cell maturation. It is possible to genetically label individual transfected epidermal cells with a reporter gene. Cotransfection experiments with STS and reporter gene vectors show that the cohort of transfected cells had a tendency to develop less rapidly since they became overrepresented in the smaller size classes at the same time the total population was somewhat shifted toward higher cell sizes. We interpret these results as an indication that restoration of the enzymatic activity induces a more normal maturation of the transfected keratinocytes.