X linked ichthyosis skin#
The skin of most neonates with X-linked ichthyosis appears normal however, within the first 3 months of life, they develop large, adherent, dirty brown scale on the trunk and extremities. Delayed or prolonged labor may be an early sign of X-linked ichthyosis due to absence of steroid sulfatase in the placenta. Without the breakdown of cholesterol sulfate by steroid sulfatase in the epidermis, corneocytes are not able to shed appropriately leading to retention of skin and excess scaling.
This defect leads to a deficiency of the steroid sulfatase enzyme. It affects almost exclusively males and is caused by deletion mutations of the STS (formerly known as ARSC1) gene on the short arm of the X chromosome.
X-linked ichthyosis is inherited in an X-linked recessive pattern. Taraska, in Brenner's Encyclopedia of Genetics (Second Edition), 2013 X-Linked Ichthyosis (Search under each name for more information on that disorder in the Rare Disease Database.C. Other forms of ichthyosis include Sjogren-Larsson syndrome, Netherton syndrome, ichthyosis hystrix, lamellar ichthyosis, Darier disease, and epidermolytic hyperkeratosis. (For more information, choose “Ichthyosis Congenita” as your search term in the Rare Disease Database.) Skin on the palms of the hands and soles of the feet can be abnormally thick. Itchiness (pruritus) usually also develops. It is characterized by generalized, abnormally red, dry, and rough skin with large coarse and fine white scales. Ichthyosis congenita (collodion baby congenital ichthyosiform erythroderma xeroderma desquamation of the newborn) is an inherited skin disorder. (See “Ichthyosis” in the Rare Disease Database.) These cells can be thought of as bricks, while the matrix would be the mortar holding these cells together. The conversion of an abnormally large number of epidermal cells into squamous cells is thought to be caused by a defect in the metabolism of the skin cells known as “corneocytes” or the fat-rich matrix around these cells. They are characterized by an abnormal accumulation of large amounts of dead skin cells (squames) in the top layer of the skin. “Ichthyoses” or “disorders of cornification” are general terms describing a group of scaly skin disorders. Comparisons can be useful for a differential diagnosis. Symptoms of the following disorders may be similar to those of X-linked ichthyosis. Low serum estriol levels detected by prenatal screening suggest the presence of a fetus with X-linked ichthyosis. The enzyme defect can cause a decrease in production of maternal estriol in late pregnancy, which may affect labor and delivery. Women who are carriers of X-linked ichthyosis and give birth to sons with the disorder may experience a delay in labor or failure of labor to initiate. These men may be at increased risk for contracting malignancies of the testes. Symptoms can improve markedly in the summer months and warm humid climates.Ī small percentage of males may experience undescended testes (crytpchordism). In about half of adult males, comma-shaped corneal opacities occur in the eyes (seen on exam by an ophthalmologist), but they do not interfere with vision. The face, scalp, palms and soles, and hollows of the elbows and knees are usually spared. The back and legs are most frequently involved early. Brownish scales that adhere to the skin are among the first signs of the disorder. The skin symptoms generally appear within the first year of life.
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