Genomic Imprinting & Uniparental Disomy

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 Genomic Imprinting 

Differential expression based on parent of origin.

Deletion 15q (11-13)

• If Paternal - Prader–Willi syndrome.
• If Maternal - Angelman syndrome  

Prader-Willi Syndrome

• Obesity
• Hypotonia 
• Small hands and feet
• Mental retardation
• Hypogonadism

Angelman = Happy puppet sundrome

• Normal at birth
• Seizures
• Mental retardation
• Ataxia
• Microcephaly
• Inappropriate Laugh

 Uniparental Disomy 

If both abnormal alleles from single parent.
egs:
1. Some cases of Cystic Fibrosis
2. Sickle cell anaemia
3. 10% cases of  Prader–Willi syndrome & Angelman syndrome
Note :
Paternal disomy - Angelman (unlike deletion)
Maternal disomy - Prader-Willi

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