Genomic imprinting seen in?
Ans. is 'a' i.e., Angleman syndrome Genomic imprinting* A person inherits two copies of their genes, one from mother and one from father. Usually both alleles of gene are active in cells. However, in some cases, one of the allele (either maternal or paternal) is silenced and only the counterpart remains active.* Thus genomic imprinting leads to preferential expression of an allele depending on its parental origin* Important examples of genomic imprinting are1) Prader Willi syndrom# It is due to paternal genomic imprinting which means there is only functional maternal gene and nonfunctional paternal gene, which may be due to either of twoi) Deletion on paternal chromosome 15 (Paternal genomic imprinting): It occurs in 70%.ii) Inharitance of both 15 chromosomes from mother and none from father (maternal uniparental disomy): in 30%.2) Anglemann syndrome# It is due to maternal genomic imprinting which means there is only functional paternal gene and nonfunctional maternal gene, which may be due to either of twoi) Deletion on maternal chromosome-15 (Maternal genomic imprinting).ii) Inheritance of both 15 chromosomes from father (Paternal uniparental disomy).
Angelman syndrome
Turner syndrome
Fragile-X syndrome
Noonan syndrome
Genetics