chr16-87891876-A-G

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2PP3_StrongPP5

The NM_001739.2(CA5A):​c.697T>C​(p.Ser233Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000324 in 1,574,768 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. S233S) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000035 ( 0 hom. )

Consequence

CA5A
NM_001739.2 missense

Scores

6
3
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:1O:1

Conservation

PhyloP100: 8.49

Publications

3 publications found
Variant links:
Genes affected
CA5A (HGNC:1377): (carbonic anhydrase 5A) Carbonic anhydrases (CAs) are a large family of zinc metalloenzymes that catalyze the reversible hydration of carbon dioxide. They participate in a variety of biological processes, including respiration, calcification, acid-base balance, bone resorption, and the formation of aqueous humor, cerebrospinal fluid, saliva, and gastric acid. They show extensive diversity in tissue distribution and in their subcellular localization. CA VA is localized in the mitochondria and expressed primarily in the liver. It may play an important role in ureagenesis and gluconeogenesis. CA5A gene maps to chromosome 16q24.3 and an unprocessed pseudogene has been assigned to 16p12-p11.2. [provided by RefSeq, Jul 2008]
CA5A Gene-Disease associations (from GenCC):
  • hyperammonemic encephalopathy due to carbonic anhydrase VA deficiency
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.97
PP5
Variant 16-87891876-A-G is Pathogenic according to our data. Variant chr16-87891876-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 127087.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CA5ANM_001739.2 linkc.697T>C p.Ser233Pro missense_variant Exon 6 of 7 ENST00000649794.3 NP_001730.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CA5AENST00000649794.3 linkc.697T>C p.Ser233Pro missense_variant Exon 6 of 7 NM_001739.2 ENSP00000498065.2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152126
Hom.:
0
Cov.:
32
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000102
AC:
2
AN:
196968
AF XY:
0.00000931
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000518
Gnomad NFE exome
AF:
0.0000114
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000351
AC:
50
AN:
1422642
Hom.:
0
Cov.:
31
AF XY:
0.0000425
AC XY:
30
AN XY:
705944
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31536
American (AMR)
AF:
0.00
AC:
0
AN:
38500
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25316
East Asian (EAS)
AF:
0.00
AC:
0
AN:
36488
South Asian (SAS)
AF:
0.0000123
AC:
1
AN:
80998
European-Finnish (FIN)
AF:
0.0000388
AC:
2
AN:
51604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5256
European-Non Finnish (NFE)
AF:
0.0000420
AC:
46
AN:
1094168
Other (OTH)
AF:
0.0000170
AC:
1
AN:
58776
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.504
Heterozygous variant carriers
0
3
6
10
13
16
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
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:
0.00000657
AC:
1
AN:
152126
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74292
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15268
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5170
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
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
Alfa
AF:
0.000126
Hom.:
0
Bravo
AF:
0.0000189

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:1Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Hyperammonemic encephalopathy due to carbonic anhydrase VA deficiency Pathogenic:1Uncertain:1Other:1
Sep 26, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with proline, which is neutral and non-polar, at codon 233 of the CA5A protein (p.Ser233Pro). This variant is present in population databases (rs587777316, gnomAD 0.005%). This missense change has been observed in individual(s) with carbonic anhydrase VA deficiency (PMID: 24530203). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 127087). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CA5A protein function. Experimental studies have shown that this missense change affects CA5A function (PMID: 24530203, 26913920). 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. -

-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

Mar 06, 2014
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

not provided Pathogenic:1
Aug 11, 2022
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Published functional studies demonstrate a damaging effect of p.(S233P) on enzymatic activity of carbonic anhydrase VA (van Karnebeek et al., 2014); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26913920, 24530203) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.95
BayesDel_addAF
Pathogenic
0.46
D
BayesDel_noAF
Pathogenic
0.42
CADD
Uncertain
25
DANN
Uncertain
1.0
Eigen
Pathogenic
0.80
Eigen_PC
Uncertain
0.59
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Benign
0.15
T
M_CAP
Pathogenic
0.70
D
MetaRNN
Pathogenic
0.97
D
PhyloP100
8.5
ClinPred
0.99
D
GERP RS
4.3
Varity_R
0.92
Mutation Taster
=16/84
disease causing (ClinVar)

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: rs587777316; hg19: chr16-87925482; API