Physiology & Biochemistry · single question
Which syndrome causes deformity of the lower jaw, ear deformity, and hearing loss?
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Correct answer: A. Treacher-Collins syndrome (Mandibulofacial Dysostosis)
✓ A) Treacher-Collins syndrome is correct.
Treacher-Collins syndrome (mandibulofacial dysostosis) — autosomal dominant, TCOF1 gene — features: mandibular and malar (cheekbone) hypoplasia, downward-slanting palpebral fissures, ear deformities (microtia/anotia) with associated conductive hearing loss, and cleft palate. It results from failed migration of neural crest cells to the first and second branchial arches. Crouzon syndrome features craniosynostosis with midface hypoplasia, prominent eyes (exophthalmos), but normal hearing and ears.
Treacher-Collins syndrome (mandibulofacial dysostosis) — autosomal dominant, TCOF1 gene — features: mandibular and malar (cheekbone) hypoplasia, downward-slanting palpebral fissures, ear deformities (microtia/anotia) with associated conductive hearing loss, and cleft palate. It results from failed migration of neural crest cells to the first and second branchial arches. Crouzon syndrome features craniosynostosis with midface hypoplasia, prominent eyes (exophthalmos), but normal hearing and ears.
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