7-50495371-T-A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP2PP3_ModeratePP5

The NM_001082971.2(DDC):​c.923A>T​(p.Asn308Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000682 in 1,613,220 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).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

DDC
NM_001082971.2 missense

Scores

8
9
2

Clinical Significance

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

Conservation

PhyloP100: 7.15

Publications

2 publications found
Variant links:
Genes affected
DDC (HGNC:2719): (dopa decarboxylase) The encoded protein catalyzes the decarboxylation of L-3,4-dihydroxyphenylalanine (DOPA) to dopamine, L-5-hydroxytryptophan to serotonin and L-tryptophan to tryptamine. Defects in this gene are the cause of aromatic L-amino-acid decarboxylase deficiency (AADCD). AADCD deficiency is an inborn error in neurotransmitter metabolism that leads to combined serotonin and catecholamine deficiency. Multiple alternatively spliced transcript variants encoding different isoforms have been identified for this gene. [provided by RefSeq, Jun 2011]
DDC Gene-Disease associations (from GenCC):
  • aromatic L-amino acid decarboxylase deficiency
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae), G2P

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 27 curated pathogenic missense variants (we use a threshold of 10). The gene has 8 curated benign missense variants. Gene score misZ: 0.40928 (below the threshold of 3.09). Trascript score misZ: 1.0771 (below the threshold of 3.09). GenCC associations: The gene is linked to aromatic L-amino acid decarboxylase deficiency.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.898
PP5
Variant 7-50495371-T-A is Pathogenic according to our data. Variant chr7-50495371-T-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 568083.We mark this variant Likely_pathogenic, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DDCNM_001082971.2 linkc.923A>T p.Asn308Ile missense_variant Exon 9 of 15 ENST00000444124.7 NP_001076440.2 P20711-1Q53Y41A0A0S2Z3N4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
DDCENST00000444124.7 linkc.923A>T p.Asn308Ile missense_variant Exon 9 of 15 1 NM_001082971.2 ENSP00000403644.2 P20711-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152226
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000239
AC:
6
AN:
251344
AF XY:
0.0000368
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000173
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000684
AC:
10
AN:
1460994
Hom.:
0
Cov.:
30
AF XY:
0.0000124
AC XY:
9
AN XY:
726840
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33452
American (AMR)
AF:
0.000157
AC:
7
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86224
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5430
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1111592
Other (OTH)
AF:
0.00
AC:
0
AN:
60340
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.470
Heterozygous variant carriers
0
1
2
3
4
5
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:
152226
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74370
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000241
AC:
1
AN:
41472
American (AMR)
AF:
0.00
AC:
0
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
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: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Deficiency of aromatic-L-amino-acid decarboxylase Pathogenic:1Uncertain:1
Jul 06, 2023
Mendelics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 30, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces asparagine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 308 of the DDC protein (p.Asn308Ile). This variant is present in population databases (no rsID available, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with DDC-related conditions. ClinVar contains an entry for this variant (Variation ID: 568083). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt DDC protein function with a positive predictive value of 80%. 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. -

not provided Uncertain:1
Oct 31, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Has not been previously published as pathogenic or benign to our knowledge; In silico analysis supports that this missense variant has a deleterious effect on protein structure/function -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.84
BayesDel_addAF
Benign
-0.049
T
BayesDel_noAF
Uncertain
-0.050
CADD
Pathogenic
29
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.71
D;.;T;.;.;.;D;.
Eigen
Pathogenic
0.87
Eigen_PC
Pathogenic
0.80
FATHMM_MKL
Uncertain
0.97
D
LIST_S2
Pathogenic
0.97
.;D;D;D;.;D;D;D
M_CAP
Uncertain
0.12
D
MetaRNN
Pathogenic
0.90
D;D;D;D;D;D;D;D
MetaSVM
Uncertain
-0.21
T
MutationAssessor
Pathogenic
3.5
H;.;.;.;.;.;H;H
PhyloP100
7.1
PrimateAI
Uncertain
0.70
T
PROVEAN
Pathogenic
-7.3
D;.;.;.;D;D;D;D
REVEL
Uncertain
0.51
Sift
Pathogenic
0.0
D;.;.;.;D;D;D;D
Sift4G
Uncertain
0.011
D;D;D;D;D;D;D;D
Polyphen
1.0
D;.;.;.;.;.;D;.
Vest4
0.92
MutPred
0.67
Loss of catalytic residue at N308 (P = 0.0138);.;.;.;.;.;Loss of catalytic residue at N308 (P = 0.0138);Loss of catalytic residue at N308 (P = 0.0138);
MVP
0.85
MPC
1.1
ClinPred
0.98
D
GERP RS
5.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.97
gMVP
0.91
Mutation Taster
=6/94
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.080
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: rs375716771; hg19: chr7-50563069; API