Question

UBE3A is the critical gene underlying Angelman syndrome. Angelman syndrome can be caused by a de novodeletion of this imprinted region of chromosome 15 on the maternal chromosome. Given what you know about the bias in expression from the maternal and the paternal chromosome, deletion of the maternal copy of this region will lead to ____________, which causes Angelman syndrome.

nearly complete loss of UBE3A expression

moderate decrease in UBE3A expression

moderate increase in UBE3A expression

no change in UBE3A expression

Answer 1

Angelman syndrome results from the LOF (loss of function) or deficient expression of the UBE3A gene.

(Paternal copy of UBE3A is already silenced by the process of genomic imprinting)

So, the correct option is (a) nearly complete loss of UBE3A expression.