What are the symptoms? At or soon after birth most infants with Netherton syndrome look ‘scalded’. The skin is ‘leaky’ causing infants to lose heat, water and proteins, all of which are necessary for normal growth and development. For the most severely affected infants, the prognosis of Netherton syndrome is poor and, despite improved management of these babies, there remains a risk that the baby may not survive beyond the first six months of life. Most suffer from severe failure to thrive in the first year. The defective skin makes these babies at a higher risk of infection. Later in childhood, some develop a distinctive circular scaling on the skin known as ichthyosis linearis circumflexa. The skin condition tends to go through bouts of flaring and may be itchy, sensitive or raw and often thickened at the joints. Individuals may become distressed if the skin, especially the face, is constantly red and peeling. Between episodes, the skin may appear relatively normal. In Netherton syndrome, the hair breaks easily making it look spiky on the scalp, but microscopic hair changes are also seen on the eyelashes, eyebrows and body hair. Individuals with Netherton syndrome have a higher risk of allergies and anaphylaxis. Some individuals are allergic to foods such as fish and nuts or are prone to hay fever, asthma and eczema-like rashes. Children with Netherton syndrome have high levels of IgE (an allergy antibody) in their blood and suffer attacks of agioedema (allergy-induced swelling). Individuals with Netherton syndrome are usually shorter than average and may have difficulty gaining weight. Gastrointestinal problems, such as diarrhoea, occur often, especially in early infancy. What are the causes? This is a genetic disorder caused by the lack of a specific protein called LEKTI (lympho-epithelial kazal type related inhibitor), which is a serine protease inhibitor. The absence of this protein leads to a profound defect in the outermost part of the skin, ‘the skin barrier’. How is it diagnosed? The diagnosis is based on clinical features, a skin biopsy (where a small amount of skin is removed for analysis) to show microscopic features in keeping with Netherton syndrome, an antibody test on the skin sample demonstrating the absence of LEKTI and molecular genetic studies on blood DNA confirming the presence of the genetic mutation in the gene responsible for the LEKTI protein. How is it treated? The main issue is the integrity of the skin barrier which can be improved by the regular, two-to-four-times daily, application of a greasy ointment-based moisturiser. In most children, the skin has a tendency to improve with age, although the basic problem persists. There is no specific treatment as yet available. Research is actively exploring ways of replacing the missing protein in the skin. There are various potential methods including a topical ointment containing the protein, gene therapy or from stem cell research. A specific treatment is still some way off but undoubtedly achievable in time. Inheritance patterns and prenatal diagnosis Inheritance patternsNetherton syndrome is inherited as an autosomal recessive trait. The gene, which is defective in this condition, is called SPINK5 and is located on chromosome 5. Prenatal diagnosisThis is available using molecular genetic analysis. Is there support? Information and support in the UK for Netherton syndrome is provided by the Ichthyosis Support Group (see entry Ichthyosis).