Tay–Sachs disease is a severe autosomal recessive genetic disease that produces deafness, blindness, seizures, and, eventually, death at 2 to 3 years of age. The disease results from a defect in the HEXA gene, which encodes hexosaminidase A. This enzyme normally degrades GM2 gangliosides. In the absence of hexosaminidase A, GM2 gangliosides accumulate in the brain. The results of molecular studies showed that the most common mutation causing Tay–Sachs disease is a 4-bp insertion that produces a downstream premature stop codon. Results of further studies have revealed that the transcription of the HEXA gene is normal in people who have Tay–Sachs disease, but the HEXA mRNA is unstable. Propose a mechanism to account for how a premature stop codon could cause mRNA instability.

Tay–Sachs disease is a severe autosomal recessive genetic disease that produces deafness, blindness, seizures, and, eventually, death at 2 to 3 years of age. The disease results from a defect in the HEXA gene, which encodes hexosaminidase A. This enzyme normally degrades GM2 gangliosides. In the absence of hexosaminidase A, GM2 gangliosides accumulate in the brain. The results of molecular studies showed that the most common mutation causing Tay–Sachs disease is a 4-bp insertion that produces a downstream premature stop codon. Results of further studies have revealed that the transcription of the HEXA gene is normal in people who have Tay–Sachs disease, but the HEXA mRNA is unstable. Propose a mechanism to account for how a premature stop codon could cause mRNA instability.

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Description: Tay–Sachs disease is a severe autosomal recessive genetic disease that produces deafness, blindness, seizures, and, eventually, death at 2 to 3 years of age. The disease results from a defect in the HEXA gene, which encodes hexosaminidase A. This enz

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter15: Genomes And Genomics

Section: Chapter Questions

Problem 12QP: One unexpected result of the sequencing of the human genome was the finding that mutations in a...

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