4-41746265-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_003924.4(PHOX2B):​c.487G>A​(p.Ala163Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,612,326 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. 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. A163S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

PHOX2B
NM_003924.4 missense

Scores

5
13

Clinical Significance

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

Conservation

PhyloP100: 1.66

Publications

4 publications found
Variant links:
Genes affected
PHOX2B (HGNC:9143): (paired like homeobox 2B) The DNA-associated protein encoded by this gene is a member of the paired family of homeobox proteins localized to the nucleus. The protein functions as a transcription factor involved in the development of several major noradrenergic neuron populations and the determination of neurotransmitter phenotype. The gene product is linked to enhancement of second messenger-mediated activation of the dopamine beta-hydroylase, c-fos promoters and several enhancers, including cyclic amp-response element and serum-response element. Expansion of a 20 amino acid polyalanine tract in this protein by 5-13 aa has been associated with congenital central hypoventilation syndrome. [provided by RefSeq, Jul 2016]
PHOX2B Gene-Disease associations (from GenCC):
  • central hypoventilation syndrome, congenital, 1, with or without Hirschsprung disease
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, G2P
  • Haddad syndrome
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
  • neuroblastoma, susceptibility to, 2
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P
  • congenital central hypoventilation syndrome
    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 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.24220571).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003924.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
PHOX2B
NM_003924.4
MANE Select
c.487G>Ap.Ala163Thr
missense
Exon 3 of 3NP_003915.2

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
PHOX2B
ENST00000226382.4
TSL:1 MANE Select
c.487G>Ap.Ala163Thr
missense
Exon 3 of 3ENSP00000226382.2
PHOX2B
ENST00000510424.2
TSL:3
n.308G>A
non_coding_transcript_exon
Exon 3 of 3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152190
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:
0.00000410
AC:
1
AN:
243994
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000291
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:
6.85e-7
AC:
1
AN:
1460136
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
726444
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33470
American (AMR)
AF:
0.0000224
AC:
1
AN:
44704
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26110
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52232
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5752
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111726
Other (OTH)
AF:
0.00
AC:
0
AN:
60200
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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

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:
152190
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74360
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), 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

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:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000167
AC:
2

ClinVar

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

Submissions by phenotype

Haddad syndrome Uncertain:1
Apr 28, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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 alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 163 of the PHOX2B protein (p.Ala163Thr). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with PHOX2B-related conditions. ClinVar contains an entry for this variant (Variation ID: 535768). 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 not expected to disrupt PHOX2B protein function.

Hereditary cancer-predisposing syndrome Uncertain:1
Aug 01, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A163T variant (also known as c.487G>A), located in coding exon 3 of the PHOX2B gene, results from a G to A substitution at nucleotide position 487. The alanine at codon 163 is replaced by threonine, an amino acid with similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.18
BayesDel_addAF
Benign
0.00083
T
BayesDel_noAF
Benign
-0.15
CADD
Uncertain
23
DANN
Uncertain
0.99
DEOGEN2
Benign
0.21
T
Eigen
Benign
-0.25
Eigen_PC
Benign
-0.26
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Benign
0.60
T
M_CAP
Uncertain
0.22
D
MetaRNN
Benign
0.24
T
MetaSVM
Uncertain
-0.038
T
MutationAssessor
Benign
1.4
L
PhyloP100
1.7
PrimateAI
Uncertain
0.62
T
PROVEAN
Benign
-0.67
N
REVEL
Benign
0.29
Sift
Benign
0.20
T
Sift4G
Benign
0.23
T
Polyphen
0.91
P
Vest4
0.27
MVP
0.68
MPC
1.1
ClinPred
0.74
D
GERP RS
4.0
Varity_R
0.17
gMVP
0.81
Mutation Taster
=62/38
polymorphism

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: rs767837376; hg19: chr4-41748282; COSMIC: COSV56931497; COSMIC: COSV56931497; API