17-68522799-G-C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_002734.5(PRKAR1A):​c.221G>C​(p.Arg74Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,802 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R74H) has been classified as Benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

PRKAR1A
NM_002734.5 missense

Scores

4
2
12

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 4.85

Publications

8 publications found
Variant links:
Genes affected
PRKAR1A (HGNC:9388): (protein kinase cAMP-dependent type I regulatory subunit alpha) cAMP is a signaling molecule important for a variety of cellular functions. cAMP exerts its effects by activating the cAMP-dependent protein kinase, which transduces the signal through phosphorylation of different target proteins. The inactive kinase holoenzyme is a tetramer composed of two regulatory and two catalytic subunits. cAMP causes the dissociation of the inactive holoenzyme into a dimer of regulatory subunits bound to four cAMP and two free monomeric catalytic subunits. Four different regulatory subunits and three catalytic subunits have been identified in humans. This gene encodes one of the regulatory subunits. This protein was found to be a tissue-specific extinguisher that down-regulates the expression of seven liver genes in hepatoma x fibroblast hybrids. Mutations in this gene cause Carney complex (CNC). This gene can fuse to the RET protooncogene by gene rearrangement and form the thyroid tumor-specific chimeric oncogene known as PTC2. A nonconventional nuclear localization sequence (NLS) has been found for this protein which suggests a role in DNA replication via the protein serving as a nuclear transport protein for the second subunit of the Replication Factor C (RFC40). Several alternatively spliced transcript variants encoding two different isoforms have been observed. [provided by RefSeq, Jan 2013]
PRKAR1A Gene-Disease associations (from GenCC):
  • Acrodysostosis 1 with or without hormone resistance
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • acrodysostosis with multiple hormone resistance
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Illumina, Orphanet
  • Carney complex, type 1
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • pigmented nodular adrenocortical disease, primary, 1
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics
  • acrodysostosis
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Carney complex
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • familial atrial myxoma
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • primary pigmented nodular adrenocortical disease
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PRKAR1ANM_002734.5 linkc.221G>C p.Arg74Pro missense_variant Exon 3 of 11 ENST00000589228.6 NP_002725.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PRKAR1AENST00000589228.6 linkc.221G>C p.Arg74Pro missense_variant Exon 3 of 11 1 NM_002734.5 ENSP00000464977.2

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461802
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727190
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111956
Other (OTH)
AF:
0.00
AC:
0
AN:
60388
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Carney complex, type 1 Uncertain:1
Sep 11, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been reported in the literature in individuals affected with PRKAR1A-related conditions. ClinVar contains an entry for this variant (Variation ID: 648708). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 74 of the PRKAR1A protein (p.Arg74Pro). This variant is not present in population databases (gnomAD no frequency).

Hereditary cancer-predisposing syndrome Uncertain:1
Sep 11, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R74P variant (also known as c.221G>C), located in coding exon 2 of the PRKAR1A gene, results from a G to C substitution at nucleotide position 221. The arginine at codon 74 is replaced by proline, an amino acid with dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.15
BayesDel_addAF
Pathogenic
0.27
D
BayesDel_noAF
Pathogenic
0.15
CADD
Benign
20
DANN
Benign
0.97
DEOGEN2
Benign
0.0021
T;T;T;T;T;T;T;.;T;T;.;.
Eigen
Benign
-0.28
Eigen_PC
Benign
-0.10
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.89
D;.;D;D;.;.;D;D;D;.;D;D
M_CAP
Benign
0.041
D
MetaRNN
Uncertain
0.44
T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.59
T
MutationAssessor
Benign
0.0
.;N;N;.;N;N;.;.;.;N;.;N
PhyloP100
4.8
PrimateAI
Benign
0.40
T
PROVEAN
Benign
0.0
.;N;N;.;.;N;.;.;.;.;.;.
REVEL
Benign
0.0
Sift
Pathogenic
0.0
.;T;T;.;.;T;.;.;.;.;.;.
Sift4G
Benign
0.45
T;T;T;T;T;T;T;T;T;T;T;T
Vest4
0.0
ClinPred
0.62
D
GERP RS
3.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.18
gMVP
0.53

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs200069356; hg19: chr17-66518940; API