Tietz syndrome
Template:Short description Template:Distinguish Template:Infobox medical condition (new) Tietz syndrome, also called Tietz albinism-deafness syndrome or albinism and deafness of Tietz,<ref name=omim>Template:OMIM</ref> is an autosomal dominant<ref name=tad/> congenital disorder characterized by deafness and leucism.<ref name="Bolognia">Template:Cite book</ref> It is caused by a mutation in the microphthalmia-associated transcription factor (MITF) gene.<ref name=tad>Template:Cite journal</ref><ref name="pmid9546825">Template:Cite journal</ref> Tietz syndrome was first described in 1963 by Walter Tietz (1927–2003), a German physician working in California.<ref name="pmid13985019">Template:Cite journal</ref>
Presentation
Tietz syndrome is characterized by profound hearing loss from birth, white hair and pale skin (hair color may darken over time to blond or red).Template:Cn
The hearing loss is caused by abnormalities of the inner ear (sensorineural hearing loss) and is present from birth. Individuals with Tietz syndrome often have skin and hair color that is lighter than those of other family members.
Tietz syndrome also affects the eyes. The iris in affected individuals is blue, and specialized cells in the eye called retinal pigment epithelial cells lack their normal pigment. The changes to these cells are generally detectable only by an eye examination; it is unclear whether the changes affect vision.<ref>Template:Cite web</ref>
Cause
Tietz syndrome is caused by mutations in the MITF gene, located on human chromosome 3p14.1-p12.3.<ref name="tad"/><ref name="pmid9546825"/><ref>Template:OMIM</ref> It is inherited in an autosomal dominant manner.<ref name=tad/> This indicates that the defective gene responsible for a disorder is located on an autosome (chromosome 3 is an autosome), and only one copy of the defective gene is sufficient to cause the disorder, when inherited from a parent who has the disorder.Template:Citation needed
Treatment
There is currently no treatment or cure for Tietz syndrome. The symptom most likely to be of practical importance is sensorineural deafness, and this is treated as any other irreversible deafness would be. In marked cases, there may be cosmetic issues. Other abnormalities (neurological, structural, Hirschsprung's disease) associated with the syndrome are treated symptomatically.
See also
References
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External links
Template:Pigmentation disorders Template:Transcription factor/coregulator deficiencies