BWS SRS

Question 1

Under normal conditions H19 is expressed from which allele

Answer 1

Maternal. CTFC binds to unmethylated domain. The paternal allele is methylated preventing ctfc binding

Question 2

Under normal conditions how are IC1/2 methylated

Answer 2

IC1 is paternally methylated
IC2 is maternally methylated

Question 3

CDKN1C is normally expressed from the ? allele

Answer 3

Maternal

Question 4

Methylation of IC2 ….

Answer 4

Likely represses expression of KCNQ1OT1, KCNQ1 and CDKN1C are expressed

Question 5

Mechanisms for BWS

Answer 5

iC1 methylation
IC2 loss of methylation
Paternal UPD 11p15 - IC1 is methylated IC2 is not
CDKN1C mutation

Question 6

Rare cases of SRS

Answer 6

Maternal Duplication of CDKN1C resulting in increased dosage and growth retardation,
Also IGF2 lof mutation and CDKN1C gain of function variant.