rs137852546

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 18P and 1B. PVS1PP3_ModeratePP5_Very_StrongBS2_Supporting

The NM_002637.4(PHKA1):​c.3334G>T​(p.Glu1112*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000075 in 1,200,593 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 4 hemizygotes in GnomAD. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000027 ( 0 hom., 2 hem., cov: 23)
Exomes 𝑓: 0.0000055 ( 0 hom. 2 hem. )

Consequence

PHKA1
NM_002637.4 stop_gained

Scores

2
2
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 7.82

Publications

3 publications found
Variant links:
Genes affected
PHKA1 (HGNC:8925): (phosphorylase kinase regulatory subunit alpha 1) Phosphorylase kinase is a polymer of 16 subunits, four each of alpha, beta, gamma and delta. The alpha subunit includes the skeletal muscle and hepatic isoforms, and the skeletal muscle isoform is encoded by this gene. The beta subunit is the same in both the muscle and hepatic isoforms, and encoded by one gene. The gamma subunit also includes the skeletal muscle and hepatic isoforms, which are encoded by two different genes. The delta subunit is a calmodulin and can be encoded by three different genes. The gamma subunits contain the active site of the enzyme, whereas the alpha and beta subunits have regulatory functions controlled by phosphorylation. The delta subunit mediates the dependence of the enzyme on calcium concentration. Mutations in this gene cause glycogen storage disease type 9D, also known as X-linked muscle glycogenosis. Alternatively spliced transcript variants encoding different isoforms have been identified in this gene. A pseudogene has been found on chromosome 1.[provided by RefSeq, Feb 2010]
PHKA1 Gene-Disease associations (from GenCC):
  • glycogen storage disease IXd
    Inheritance: XL, AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 17 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
Variant X-72582562-C-A is Pathogenic according to our data. Variant chrX-72582562-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 9923.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS2
High Hemizygotes in GnomAd4 at 2 XL,AR geneVariant has number of hemizygotes lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PHKA1NM_002637.4 linkc.3334G>T p.Glu1112* stop_gained Exon 31 of 32 ENST00000373542.9 NP_002628.2 P46020-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PHKA1ENST00000373542.9 linkc.3334G>T p.Glu1112* stop_gained Exon 31 of 32 1 NM_002637.4 ENSP00000362643.4 P46020-1

Frequencies

GnomAD3 genomes
AF:
0.0000269
AC:
3
AN:
111576
Hom.:
0
Cov.:
23
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000565
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000551
AC:
6
AN:
1089017
Hom.:
0
Cov.:
28
AF XY:
0.00000564
AC XY:
2
AN XY:
354779
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
26250
American (AMR)
AF:
0.00
AC:
0
AN:
35177
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
19318
East Asian (EAS)
AF:
0.00
AC:
0
AN:
30177
South Asian (SAS)
AF:
0.00
AC:
0
AN:
53847
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
40515
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4116
European-Non Finnish (NFE)
AF:
0.00000600
AC:
5
AN:
833809
Other (OTH)
AF:
0.0000218
AC:
1
AN:
45808
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.438
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000269
AC:
3
AN:
111576
Hom.:
0
Cov.:
23
AF XY:
0.0000592
AC XY:
2
AN XY:
33772
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
30649
American (AMR)
AF:
0.00
AC:
0
AN:
10478
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
2640
East Asian (EAS)
AF:
0.00
AC:
0
AN:
3563
South Asian (SAS)
AF:
0.00
AC:
0
AN:
2658
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
6019
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
238
European-Non Finnish (NFE)
AF:
0.0000565
AC:
3
AN:
53126
Other (OTH)
AF:
0.00
AC:
0
AN:
1522
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000189

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Glycogen storage disease IXd Pathogenic:3
Nov 01, 1994
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Nov 27, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Glu1112*) in the PHKA1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in PHKA1 are known to be pathogenic (PMID: 9731190, 15637709). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with clinical features of PHKA1-related conditions (PMID: 7874115). ClinVar contains an entry for this variant (Variation ID: 9923). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. For these reasons, this variant has been classified as Pathogenic. -

Apr 20, 2023
Duke University Health System Sequencing Clinic, Duke University Health System
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.74
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
51
DANN
Uncertain
1.0
FATHMM_MKL
Uncertain
0.95
D
PhyloP100
7.8
Vest4
0.47
GERP RS
5.1
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.96
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.96
Position offset: -3

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs137852546; hg19: chrX-71802412; API