A 12-year-old boy is evaluated in the clinic due to excessive bleeding following a tooth extraction. The patient also develops large bruises after only minor injury but has had no major bleeding episodes in the past. His maternal uncle died from an intracranial hemorrhage. Laboratory testing reveals decreased coagulation factor VIII activity levels. A referral is made to a clinical geneticist, who suspects that the patient has a deletion mutation in the enhancer sequence of the factor VIII gene. This mutation has resulted in decreased transcription of factor VIII by RNA polymerase II. Which of the following is the most accurate statement regarding the abnormal genetic sequence in this patient?

Question

A 12-year-old boy is evaluated in the clinic due to excessive bleeding following a tooth extraction.  The patient also develops large bruises after only minor injury but has had no major bleeding episodes in the past.  His maternal uncle died from an intracranial hemorrhage.  Laboratory testing reveals decreased coagulation factor VIII activity levels.  A referral is made to a clinical geneticist, who suspects that the patient has a deletion mutation in the enhancer sequence of the factor VIII gene.  This mutation has resulted in decreased transcription of factor VIII by RNA polymerase II.  Which of the following is the most accurate statement regarding the abnormal genetic sequence in this patient?

Quizplus · Accepted Answer

Eductional Objective: Enhancers and silencers may be located upstream, downstream, or within a transcribed gene; these gene sequences function to increase and decrease the rate of transcription, respectively.  In contrast, promoter regions are typically located 25 or 75 bases upstream from their associated genes and function to initiate transcription.

A 12-Year-Old Boy Is Evaluated in the Clinic Due to Excessive