7-50537883-C-T

Position:

• chr7-50537883-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_001082971.2(DDC):​c.412G>A​(p.Gly138Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,878 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 Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: DDC NM_001082971.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.29

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-AS1 (HGNC:40171): (DDC antisense RNA 1)

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a region_of_interest 2 X approximate tandem repeats (size 120) in uniprot entity DDC_HUMAN there are 8 pathogenic changes around while only 1 benign (89%) in NM_001082971.2
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.88

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DDC	NM_001082971.2	c.412G>A	p.Gly138Arg	missense_variant	4/15	ENST00000444124.7	NP_001076440.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DDC	ENST00000444124.7	c.412G>A	p.Gly138Arg	missense_variant	4/15	1	NM_001082971.2	ENSP00000403644.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251468 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135908

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461878 Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4 AN XY: 727238

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Deficiency of aromatic-L-amino-acid decarboxylase Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.010
CADD	Benign	21
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.62	D;.;T;.;.;D;.
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.97	.;D;D;D;.;D;D
M_CAP	Uncertain	0.090	D
MetaRNN	Pathogenic	0.88	D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.18	T
MutationAssessor	Uncertain	2.9	M;M;.;.;M;M;M
PrimateAI	Uncertain	0.50	T
PROVEAN	Pathogenic	-5.7	D;.;.;.;D;D;D
REVEL	Uncertain	0.35
Sift	Uncertain	0.027	D;.;.;.;T;D;D
Sift4G	Uncertain	0.029	D;D;D;D;D;D;D
Polyphen		0.98	D;.;.;.;.;D;.
Vest4		0.44
MutPred		0.78		Loss of catalytic residue at A137 (P = 0.1157);Loss of catalytic residue at A137 (P = 0.1157);Loss of catalytic residue at A137 (P = 0.1157);.;Loss of catalytic residue at A137 (P = 0.1157);Loss of catalytic residue at A137 (P = 0.1157);Loss of catalytic residue at A137 (P = 0.1157);
MVP		0.72
MPC		0.68
ClinPred		0.99	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.67
gMVP		0.94

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs886062375; hg19: chr7-50605581;