MBG 1000 Lecture 4: Week 4 - Recessive Traits, Albinism & Sickle Cell Anemia

• School: University of Guelph
• Department: Molecular Biology and Genetics
• Course: MBG 1000
• Professor: Georgevander Merwe

Document Summary

Pigment is melanin: funcion to colour and protect cells, melanin synthesized in melanocytes. Melanocytes form cellular extensions between other skin cells. Albinism = absence of pigment: skin, hair and eyes, opical nerve can be damaged. Oculocutaneous: oculo: eyes or sense of vision, cutaneous: relaing to/afecing skin. The gene that causes albinism encodes the enzyme tyrosinase: chromosome 11. Autosomal recessive disorder: heterozygotes (carriers) are asymptomaic. Many variaions of oca dependent on ability to produce and deliver melanin to target cells. Oten linked to levels of reduces acivity of tyrosinase. Pale eyes at birth, reduced reinal pigmentaion, impaired opical nerve development, vision problems: oca type 1b (oca1b) Reduced acivity of tyrosinase; gene carrier a mutaion that reduces encoded tyrosinase acivity. Hair colour varies from light yellow to light brown, light skin colour; freckles. Pale eyes at birth, develops light-coloured eyes, reduced reinal pigmentaion, impaired opical nerve development, vision problems. Oten involved loss of gene funcion: null/amorphic alleles.