Prader Willi/Angelman Syndrome – Methylation Sensitive HRM

Diagnostic Use

Prader-Willi Syndrome (PWS) (OMIM 176270) is characterised by severe hypotonia and feeding difficulties in early infancy, followed in early childhood by excessive eating, morbid obesity, delayed motor milestones, language development and cognitive impairment. Individuals also have hypogonadism, short stature, characteristic facial features and a distinctive behavioural phenotype (with temper tantrums, stubbornness, manipulative behaviour, and obsessive-compulsive characteristics).
Angelman Syndrome (AS) (OMIM 105830) is characterised by severe developmental delay or mental retardation, severe speech impairment, gait ataxia and/or tremulousness of the limbs, and a unique behaviour with an inappropriate happy demeanour that includes frequent laughing, smiling and excitability. Microcephaly and seizures are also common. The unique clinical features of AS do not become manifest until after one year of age, although developmental delay can sometimes be identified from 6 months.
These syndromes are genomic imprinting disorders associated with differentially methylated genes on chromosome 15q11.2-q13. PWS is caused by the loss of the paternal contribution of imprinted genes in 15q11.2-q13 region (gene/s unknown) and AS is caused by the loss of the maternal contribution of imprinted genes (UBE3A) in the same region.


Genetics - Molecular Pathology

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Constituent Tests



Turnaround Time

4 weeks

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