Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chromosomal Microdeletions: Prader-Willi and Angelman Syndromes

Similar presentations

Presentation on theme: "Chromosomal Microdeletions: Prader-Willi and Angelman Syndromes"— Presentation transcript:

1 Chromosomal Microdeletions: Prader-Willi and Angelman Syndromes

2 Prader-Willi Syndrome
Gene imprinted (turned off) Gene not imprinted (turned on) Maternal DNA Paternal DNA D e l t d Prader-Willi Syndrome D e l t d Angelman Syndrome

3 http://www. ncbi. nlm. nih. gov/books/bv. fcgi. tool=bookshelf&call=bv


5 Prader-Willi Syndrome
Cause: Usually caused by micro deletion in region q11-13 of the paternally transmitted chromosome 15. Several genes in this region are genomically imprinted in the maternal chromosome. Hence, if there is a paternal deletion in this region, there are no active genes. Symptoms: Short stature Mental retardation, learning difficulties Decreased muscle tone Hypogonadism Emotional lability Unregulated appetite or hyperphagia ( obesity)

6 Prader Willi Syndrome

7 Tanis, a girl with PWS

8 Angelman Syndrome Cause: Symptoms:
Microdeletion of region q11-13 of chromosome 15 that deletes a gene(s) that is paternally imprinted. Symptoms: Normal development until 6-12 months, then delayed development Disproportionate head growth  microcephaly Abnormal EEG, seizures Marked deficit in language (no words to a few words) but better communication using nonvebral methods (e.g., facial expressions) Motoric problems (balance problems, ataxia of gait, hypermotoric actions) Attention problems (short attention span) Emotional exuberance (frequent laughter, smiling)

9 Angelman Syndrome

10 Angelman Syndrome

Download ppt "Chromosomal Microdeletions: Prader-Willi and Angelman Syndromes"

Similar presentations

Ads by Google