V

Unknown defect

All tests negative

15%

Unclear

Unclear

aMT=DNA methylation testing.

aMT=DNA methylation testing.

proteolytic pathway where the proteolysis occurs after conjugation to ubiquitin.[24] This gene is imprinted in the brain where only its maternal allele is functional.1-25-1 A mouse model of AS was developed by generating a UBE3A null mutation. The affected mice show cognitive impairments, inducible seizures, and deficit in long-term potentiation.1-26-1 Still at this time a direct link between the UBE3A deficiency and the clinical features of AS has not been positively established.

Phenotype-Genotype Correlations

The most severe AS phenotype is observed in Type I (deletion) patients. The clinical severity in this group is believed to be due to additional deleted genes in this region. For example, the severity of seizure disorder may be due to the deletion of the GABA receptor gene GABRB3, which is located in the deleted area;[27] the hypopigmentation is linked to the deleted P gene in this area.[28] The UPD patients form the other end of the clinical spectrum with the mildest phenotypes. The severity in patients with imprinting defects and UBE3A mutations seems to fall between the deletion and UPD categories.

Diagnostic Testing

The diagnostic tests bellow are listed in order of their application for diagnostic evaluation (Table 1 and Fig. 2):

• G-banded chromosome analysis should be undertaken in every individual with suspected AS for two

DNA methylation and chromosome analysis

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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