Diseases Flashcards
What is beta-thalassemia?
mild inherited anemia
There is a mutation in the __________ region of the b-globin gene in beta-thalassemia
promoter (less promotion = less transcription)
What is the specific mutation in beta-thalassemia?
mutation in TATA box (CATA to CATG)
What is the mutation in gamma-delta-beta thalassemia?
deletion of locus of control region for transcription of globin genes
What causes hemophilia B leyden?
problem in promoter region of protein clotting gene
Why does hemophilia B leyden improve during puberty?
alternative transcriptional activators can bind overlapping sites at the promoter (i.e.: androgen receptor)
What causes Fragile X syndrome?
Expansion of CCG gene upstream of FMR1 gene
Expansion of CCG gene upstream of FMR1 gene leads to ________
Fragile X syndrome
How does Fragile X syndrome lead to transcriptional silencing?
expansion in CCG count increases methylation; methylated DNA recruits HDACs, silences transcription
Craniosynostosis comes from a mutation in ______
homeodomain protein (helix-turn-helix) MSX2 (affects transcription of genes for craniofacial development)
What amino acid substitution occurs in craniosynostosis?
proline –> histidine (protein binds DNA more strongly, gives gain of function)
Androgen insensitivity syndrome comes from a mutation in what sequence-specific DNA binding protein?
zinc finger
In Waardenburg syndrome type II, microphthalmia-associated transcription factor (MITF) is non-functional. What protein is this defect associated with?
basic helix-loop-helix (sequence-specific DNA binding protein)
Leukemia involves a defect in ________
histone acetylation
Rubinstein-Tavbi syndrome has a mutation in a _____ that normally activates transcription for many different genes
histone acetyltransferase (HAT)
Colon cancer is caused by a mutation in ______
APC