Table 2.

Molecular Genetic Testing Used in Phosphorylase Kinase Deficiency

Gene 1, 2
(MOI)		Proportion of PhK Deficiency Attributed to Pathogenic Variants in GeneProportion of Pathogenic Variants 3 Detectable by Method
Sequence analysis 4Gene-targeted deletion/duplication analysis 5
PHKA1 (XL)Rare – muscle phenotype7/7 6Unknown 7
PHKA2 (XL)75% of individuals w/liver PhK deficiency~94% 8~6% 9
PHKB (AR)~10% of individuals w/liver PhK deficiency~96% 10~4% 11
PHKG2 (AR)~10% of individuals w/liver PhK deficiency~99% 12Unknown

AR = autosomal recessive; MOI = mode of inheritance; XL = X-linked

1.

Genes are listed in alphabetic order.

2.

See Table A. Genes and Databases for chromosome locus and protein.

3.

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

4.

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

5.

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.

6.
7.

No data on detection rate of gene-targeted deletion/duplication analysis are available.

8.
9.
10.
11.
12.

From: Phosphorylase Kinase Deficiency

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