Trichothiodystrophy (TTD) is a genetic disorder characterized by abnormal brittleness and weakness of the hair. The hair is often short, curly, and easily breakable. This disease not only affects the hair but can also present various symptoms in other parts of the body such as the skin, eyes, bones, and nervous system. TTD usually becomes apparent in childhood and is a lifelong condition.
What Causes Trichothiodystrophy?
Trichothiodystrophy typically results from mutations in genes involved in DNA repair. The most commonly affected genes include ERCC2 (XPD) and ERCC3 (XPB). These genes play a critical role in repairing cellular DNA damage. Mutations cause DNA repair mechanisms to malfunction, leading to the cells’ inability to perform their normal functions. This condition becomes particularly noticeable in rapidly dividing cells such as hair follicles.
Genetic predisposition indicates that TTD can be hereditary. It usually follows an autosomal recessive inheritance pattern, meaning that an individual must inherit mutated genes from both parents for the disease to manifest. Therefore, individuals with a family history of TTD have a higher risk of the disease.
What Are the Symptoms of Trichothiodystrophy?
The symptoms of trichothiodystrophy include:
- brittle and easily breakable hair
- short, curly, and abnormal structured hair
- eye problems (photophobia, cataracts)
- dry and scaly skin
- nail abnormalities
- growth retardation
- delayed mental and motor development
How Is Trichothiodystrophy Diagnosed?
The diagnosis of trichothiodystrophy involves clinical findings and genetic tests. Initially, the patient’s medical history and symptoms are evaluated. Brittle and abnormal hair structure provide a significant clue for diagnosis. Dermatologists can identify structural abnormalities in the hair shaft by examining the hair under a microscope.
Genetic tests are crucial for confirming TTD. Molecular genetic tests to identify mutations in DNA repair genes like ERCC2 and ERCC3 provide a definitive diagnosis. These tests are also important for understanding the hereditary nature of the disease and providing genetic counseling for family members.
Additionally, advanced imaging techniques such as skin biopsy and electron microscopy can be used. These tests support the diagnosis by showing cellular-level abnormalities and defects in DNA repair.
How Is Trichothiodystrophy Treated?
There is no specific treatment for trichothiodystrophy. Treatment consists of symptomatic approaches aimed at alleviating the disease’s symptoms and improving the quality of life. Treatment options include:
Hair and Skin Care: Appropriate hair and skin care products should be used to protect brittle hair and manage skin problems. Moisturizers and emollients can relieve skin dryness.
Eye Treatment: Patients with eye problems should be regularly monitored and treated by ophthalmologists. Protective glasses and surgical interventions may be necessary for conditions such as photophobia and cataracts.
Growth and Development Support: Children with growth retardation and developmental delays should be monitored and supported by pediatricians and physiotherapists. Nutritional counseling and physical therapy can support growth and motor skills.
Genetic Counseling: Due to the hereditary nature of TTD, families should receive genetic counseling. This is important for assessing the risk of the disease in future pregnancies and informing family members.