Other names: Pili trianguli et Canaliculi; Cheveux incoiffables; Unmanageable hair syndrome; Congenital and Genetic Diseases; Skin Diseases Summary Uncombable hair syndrome (UHS) is a rare disorder of the hair shaft of the scalp. It is usually characterized by silvery-blond or straw-colored hair that is disorderly; stands out from the scalp; and cannot be combed flat. It may first become apparent from 3 months of age to 12 years of age.[1] Most cases are isolated, but in some cases it has been described in association with other diseases, such as ectodermal dysplasias, Bork syndromeand Angel-shaped phalangoepiphyseal dysplasia. The syndrome has been found to be caused by mutations in the genes PADI3, TGM3, and TCHH. These three genes code for proteins that are involved in hair shaft formation.[2] The syndrome appears to be inherited in an autosomal recessive fashion; however, cases inherited in an autosomal dominant manner may also exist, as there are other genes involved in hair formation. The condition often spontaneously regresses in late childhood.[3] Some published studies suggest that biotin may improve the condition.[4] Symptoms Uncombable hair syndrome (UHS) may first become apparent any time between the ages of 3 months and 12 years.[3] It only affects the scalp hair. The quantity of hair remains normal, but the hair often grows slowly.[5]Over time the hair becomes progressively silvery-blond or straw-colored; dry and disordered (standing out and growing in different directions); and unmanageable to comb flat.[3] In some cases, constant efforts to groom the hair lead to breakage, but increased fragility is not a constant feature of the condition. In later childhood, there is usually a considerable amount of spontaneous improvement.[1][6] In cases where UHS is part of a syndrome, there may be other signs and symptoms present; therefore, it is important to determine whether the UHS is isolated or syndromic. Last updated: 12/19/2016 The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below. Cause Three genes have been associated with uncombable hair syndrome (UHS): PADI3, TGM3, and TCHH. These three genes code for proteins responsible for the formation of the hair shaft. In these cases, the mode of inheritance appears to be autosomal recessive. Nonetheless, other cases in which multiple family members have the condition seem to be inherited in an autosomal dominant fashion and may be caused by other genes that have yet to be identified. In the majority of cases, UHS is isolated and is not part of a syndrome. The syndromic forms of UHS are caused by other genes. Inheritance Uncombable hair syndrome (UHS) is thought to be inherited in an autosomal recessive fashion; however, there are likely cases in which the condition is inherited in an autosomal dominant manner with reduced penetrance. Autosomal dominant means that having a change (mutation) in only one copy of the responsible gene in each cell is enough to cause features of the condition. When a person with a mutation that causes an autosomal dominant condition has children, each child has a 50% (1 in 2) chance to inherit that mutation. Reduced penetrance means that not all people with a mutation in the responsible gene will have the condition. For this reason, conditions with reduced penetrance may appear to "skip a generation" or may appear to occur for the first time (or only once) in a family. While people with UHS often report a negative family history, the characteristic hair shaft abnormality seen in affected people can still be seen in unaffected family members by looking at their hair under a specific type of microscope.[1] Diagnosis A diagnosis of uncombable hair syndrome (UHS) is made by observing the characteristic symptoms of the condition, as well observing the hair shaft under a special microscope.[3] When the individual hair strands are viewed under a microscope, the hair is either triangular or kidney-shaped on cross section, and has a canal-like longitudinal groove along one or two faces.[7][1] People with concerns about symptoms of UHS are encouraged to speak with their dermatologist about being evaluated for this condition. The recent discovery of the genesassociated with the condition may lead to genetic testing in the future. Treatment There is no definitive treatment for uncombable hair syndrome, but the condition usually improves or resolves on its own with the onset of puberty. Gentle hair care is generally recommended using conditioners and soft brushes, along with avoiding harsh hair treatments such as permanent waves (perms); chemical relaxants; or excessive brushing and blow drying. These strategies may improve the general manageability of the hair, although how well they work is subjective.[6] Another strategy that has been suggested to improve the appearance of the hair is the use of biotin supplements. One case report suggested significant improvement in hair strength and combability, with an increase in rate of growth after 4 months of supplementation.[6] Prognosis Uncombable hair syndrome (UHS) usually resolves on its own (spontaneously) by adolescence.[6] Treatment is usually not necessary.[1] In the cases, where UHS is part of syndrome, the prognosis will depend on the specific syndrome and the signs and symptoms present in the person. References http://www.orpha.net/data/patho/GB/uk-uncombable.pdf. http://www.cell.com/ajhg/abstract/S0002-9297(16)30440-2. http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=1410. http://www.ncbi.nlm.nih.gov/pubmed/17526443. https://www.ncbi.nlm.nih.gov/pubmed/19700017. https://www.ncbi.nlm.nih.gov/pubmed/17845183. http://www.omim.org/entry/191480. Source
