Description, Causes and Risk Factors:
Netherton syndrome is a rare hereditary disorder characterized by scaling skin, hair anomalies, increased susceptibility to atopic eczema (a skin condition that can result in dry, red and flaky skin), elevated IgE levels, and other related symptoms. Netherton syndrome is inherited as an autosomal recessive trait.
Netherton syndrome is caused by a mutation in the SPINK5 [SPINK5 is a member of a gene family cluster located on chromosome 5q33.1, which encode inhibitors of serine proteases. This includes other epidermal proteins SPINK6 and LEKTI-2 (SPINK9). The SPINK5 gene is 61 kb in length and contains 33 exons. Alternative processing of SPINK5 results in the formation of three different gene products, which have been identified in differentiated keratinocytes] gene, located on the long arm of chromosome 5 (5q). This gene codes for the production of a protein LEKTI, found in the skin and thymus. LEKTI inhibits certain enzymes in the outermost layer of the skin. The function of these enzymes is to break down the links holding together horny skin cells, facilitating the normal process by which skin cells are shed. LEKTI deficiency leads to excessive shedding of horny skin cells, and as a result the skin becomes thin, red and scaly. The permeability of the skin increases, causing dryness. The barrier function of the skin is impaired and chemicals, including those in ointments and creams, can pass easily through the skin. The presence of LEKTI is also required for normal hair growth and for the maturation of certain white blood corpuscles in the child's thymus. All the symptoms of Netherton syndrome are associated with impaired levels of this particular enzyme inhibitor.
Netherton's syndrome usually appears out of the blue with no history of such a condition in the family. It is a genetic disease where the parents are each “carriers” of the faulty gene or have a single dose of the gene and unfortunately they both pass it onto the child who has a double dose of the gene. For parents with an affected child there is a one in four chance of any future baby being affected with the same condition. Girls tend to be less severely affected than boys. There is no way of preventing or reliably detecting it before birth. There is research in progress to try and identify the causative gene but as there are millions of genes it is a complicated and slow business.
The incidence of Netherton syndrome has not been conclusively established, but it is estimated that there are currently approximately 10 to 15 individuals with the disorder in Sweden.
Most affected infants are “scalded-looking” at birth (congenital erythroderma) and are slow to gain weight, especially in the first year of life. They may, as a result, be kept in hospital until they are growing, perhaps weeks or even months. Their skin is very “leaky” and loses heat, water and protein. These babies may need to be kept in incubators in the special care unit for some time and will need extra fluids and food to compensate. They are more at risk to infection because of their inflamed skin. Skin treatment means regular gentle cleansing, moisturizing and careful handling.
Patients with Netherton's syndrome have fragile, spiky hair which seems to grow very slowly. This affects the scalp hair, eyebrows, eyelashes and body hair and is a clue to diagnosis. If the “odd-looking” hair is noticed early on it can be examined under the microscope when is shows a characteristic structure due to “bamboo” swellings on the shaft. This sign clinches the diagnosis even in a baby and the swellings are due to areas of weakness and “telescoping” of the hair. This is why the hair breaks so easily. Many children with Netherton's syndrome become allergic to foods such as fish and nuts and will also notice that they have swellings of the face or lips when in contact with, or are near to the offending items. Hay fever can occur and the children have high levels of the allergy antibody (lgE) in their blood. They are usually shorter and lighter than other children and may not be as active in sports activities as they easily overheat. Their performance should not be unduly affected but life can be difficult if the skin, especially the face, is constantly red and peeling.
Netherton syndrome is an extremely rare condition, and for a long time it was often misdiagnosed. In the past, children with the syndrome were misdiagnosed with, for example, Leiner syndrome, acrodermatitis enteropathica (zinc deficiency), or erythrodermic eczema.
Today the diagnosis is usually based on symptoms manifesting in the newborn child, and the results of specific blood analyses (high sodium and IgE levels). Hair abnormalities are visible under a regular microscope, but not all hairs are affected and typical abnormalities may not be evident at birth. It is therefore advisable to carry out repeated examinations from different parts of the head during the first few months of the infant's life.
Blood tests or puncture tests (in which suspected allergens are allowed to enter the skin through a gentle needle prick) can be used to determine various allergies.
The diagnosis is confirmed by examining LEKTI in a skin biopsy and by a DNA analysis to prove the presence of a mutation on the SPINK5 gene. If the mutation in the SPINK5 gene is identified, prenatal diagnostics is possible.
There is no cure as the cause is not known but intensive nursing care in infancy and continued care with moisturizers and anti-infective treatments when necessary will keep the skin as good as possible. Dietary supplements, especially protein, are often needed in early childhood and extra help with physiotherapy and teaching should be available if needed. Our experience shows that usual treatments for inflamed skin, such as steroid creams or retinoid medicines are ineffective in Netherton's syndrome and indeed may make things worse.
NOTE: The above information is for processing purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.