๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
Trichothiodystrophy
Trichothiodystrophy
Clinical features Pollit and colleagues described TTD in 1968 as a rare group of autosomal recessive disorders presenting in children and characterized by short, fragile, brittle hair associated with a variety of other hair shaft abnormalities.1,2 Clinically, it is a heterogeneous condition with frequent systemic manifestations predominantly affecting organs derived from the neuroectoderm. Hairs, which have low sulfur content, break easily with resultant hair loss. Changes of trichorrhexis nodosa are usually evident in the proximal portion of the hair shaft.
TTD is a feature of many syndromes including BIDS (brittle sulfur-deficient hair, intellectual impairment, decreased fertility and short stature), IBIDS (ichthyosis and BIDS), PIBIDS (photosensitivity and IBIDS), SIBIDS (otosclerosis and IBIDS), ONMR (onychotrichodysplasia, chronic
TTD may be diagnosed in utero by a fetal eyebrow biopsy or from amniotic fluid trophoblasts by identifying defects in the DNA repair capacity.25โ27