Table 1.

Molecular Genetic Testing Used in GNB1 Encephalopathy

Gene 1MethodProportion of Probands with a Pathogenic Variant 2, 3 Detectable by Method
GNB1 Sequence analysis 457/58 5
Gene-targeted deletion/duplication analysis 61/58 7
1.
2.

See Molecular Genetics for information on allelic variants detected in this gene.

3.

Individuals with contiguous gene deletions, including 1p36 microdeletion, are not included in these calculations (see Genetically Related Disorders).

4.

Sequence analysis detects variants that are benign, likely benign, of uncertain significance, likely pathogenic, or pathogenic. Variants may include small intragenic deletions/insertions and missense, nonsense, and splice site variants; typically, exon or whole-gene deletions/duplications are not detected. For issues to consider in interpretation of sequence analysis results, click here.

5.
6.

Gene-targeted deletion/duplication analysis detects intragenic deletions or duplications. Methods used may include a range of techniques such as quantitative PCR, long-range PCR, multiplex ligation-dependent probe amplification (MLPA), and a gene-targeted microarray designed to detect single-exon deletions or duplications.

7.

One individual with an intragenic deletion spanning exons 2-5 of GNB1 is reported in the DECIPHER database [Firth et al 2009]. Limited clinical information is available on this individual. See Molecular Genetics for additional information.

From: GNB1 Encephalopathy

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